diff --git a/lib/bashly/completions/bashly-completions.bash b/lib/bashly/completions/bashly-completions.bash
index 0f85d38c..1554ab5a 100644
--- a/lib/bashly/completions/bashly-completions.bash
+++ b/lib/bashly/completions/bashly-completions.bash
@@ -301,7 +301,7 @@ _bashly_completions() {
       return
       ;;
     6:0)
-      while read -r; do COMPREPLY+=("$REPLY"); done < <(compgen -W "arg arg.allowed arg.completions arg.default arg.help arg.name arg.repeatable arg.required arg.validate command command.alias command.args command.catch_all command.commands command.completions command.default command.dependencies command.environment_variables command.examples command.expose command.extensible command.filename command.filters command.flags command.footer command.function command.group command.help command.help_header_override command.name command.private command.variables command.version environment_variable environment_variable.default environment_variable.help environment_variable.name environment_variable.private environment_variable.required environment_variable.validate flag flag.alias flag.allowed flag.arg flag.completions flag.conflicts flag.default flag.help flag.long flag.needs flag.private flag.repeatable flag.required flag.short flag.unique flag.validate variable variable.name variable.value" -- "$cur")
+      while read -r; do COMPREPLY+=("$REPLY"); done < <(compgen -W "arg arg.allowed arg.completions arg.default arg.help arg.name arg.repeatable arg.required arg.validate command command.alias command.args command.catch_all command.commands command.completions command.default command.dependencies command.environment_variables command.examples command.expose command.extensible command.filename command.filters command.flags command.footer command.function command.group command.help command.help_header_override command.name command.private command.variables command.version environment_variable environment_variable.default environment_variable.help environment_variable.name environment_variable.private environment_variable.required environment_variable.validate flag flag.alias flag.allowed flag.arg flag.completions flag.conflicts flag.default flag.help flag.long flag.needs flag.negatable flag.private flag.repeatable flag.required flag.short flag.unique flag.validate variable variable.name variable.value" -- "$cur")
       return
       ;;
     8:0)
diff --git a/lib/bashly/completions/completely.yaml b/lib/bashly/completions/completely.yaml
index 08d0697e..cf8b09bd 100644
--- a/lib/bashly/completions/completely.yaml
+++ b/lib/bashly/completions/completely.yaml
@@ -127,6 +127,7 @@ tokens:
     - flag.help
     - flag.long
     - flag.needs
+    - flag.negatable
     - flag.private
     - flag.repeatable
     - flag.required
diff --git a/lib/bashly/config_validator.rb b/lib/bashly/config_validator.rb
index 1b4481db..6aac6fdb 100644
--- a/lib/bashly/config_validator.rb
+++ b/lib/bashly/config_validator.rb
@@ -130,6 +130,7 @@ def assert_flag(key, value)
       assert_string_or_array "#{key}.default", value['default']
       assert_string_or_array "#{key}.validate", value['validate']
 
+      assert_boolean "#{key}.negatable", value['negatable']
       assert_boolean "#{key}.private", value['private']
       assert_boolean "#{key}.repeatable", value['repeatable']
       assert_boolean "#{key}.unique", value['unique']
@@ -148,6 +149,13 @@ def assert_flag(key, value)
 
       refute value['required'] && value['default'], "#{key} cannot have both nub`required` and nub`default`"
 
+      if value['negatable']
+        assert value['long'], "#{key}.negatable requires nub`long`"
+        refute value['arg'], "#{key}.negatable does not make sense with nub`arg`"
+        refute value['repeatable'], "#{key}.negatable does not make sense with nub`repeatable`"
+        refute value['required'], "#{key}.negatable does not make sense with nub`required`"
+      end
+
       if value['default']
         assert value['arg'], "#{key}.default does not make sense without nub`arg`"
       end
@@ -234,7 +242,7 @@ def assert_command(key, value)
       assert_array "#{key}.variables", value['variables'], of: :var
 
       assert_uniq "#{key}.commands", value['commands'], %w[name alias]
-      assert_uniq "#{key}.flags", value['flags'], %w[long short alias]
+      assert_uniq_flags key, value['flags']
       assert_uniq "#{key}.args", value['args'], 'name'
 
       if value['function']
@@ -276,5 +284,23 @@ def assert_command(key, value)
         refute value['extensible'], "#{key}.extensible makes no sense"
       end
     end
+
+    def assert_uniq_flags(key, flags)
+      return unless flags
+
+      list = flags.flat_map do |flag|
+        [flag['long'], flag['short'], *Array(flag['alias']), negated_flag_name(flag)].compact
+      end
+
+      nonuniqs = list.nonuniq
+      assert nonuniqs.empty?,
+        "#{key}.flags contains non-unique elements (#{nonuniqs.join ', '}) in long or short or alias"
+    end
+
+    def negated_flag_name(flag)
+      return unless flag['negatable'] == true && flag['long']
+
+      "--no-#{flag['long'].delete_prefix '--'}"
+    end
   end
 end
diff --git a/lib/bashly/docs/flag.yml b/lib/bashly/docs/flag.yml
index f7178f5c..5a27049f 100644
--- a/lib/bashly/docs/flag.yml
+++ b/lib/bashly/docs/flag.yml
@@ -147,6 +147,15 @@ flag.needs:
       help: Where to add the alias
       needs: [--add]
 
+flag.negatable:
+  help: Allow a boolean long flag to also be disabled with its `--no-` form.
+  url: https://bashly.dev/configuration/flag/#negatable
+  example: |-
+    flags:
+    - long: --color
+      help: Enable color output
+      negatable: true
+
 flag.private:
   help: Specify that this flag should not be displayed in the help text.
   url: https://bashly.dev/configuration/flag/#private
diff --git a/lib/bashly/script/flag.rb b/lib/bashly/script/flag.rb
index 7b26c3cb..e3c92ff5 100644
--- a/lib/bashly/script/flag.rb
+++ b/lib/bashly/script/flag.rb
@@ -11,7 +11,7 @@ class << self
         def option_keys
           @option_keys ||= %i[
             alias allowed arg completions conflicts default help long needs
-            private repeatable required short unique validate
+            negatable private repeatable required short unique validate
           ]
         end
       end
@@ -23,9 +23,17 @@ def alt
       end
 
       def aliases
+        [long, negated_long, short].compact + alt
+      end
+
+      def positive_aliases
         primary_aliases + alt
       end
 
+      def negated_long
+        "--no-#{long_without_prefix}" if negatable && long
+      end
+
       def default_string
         if default.is_a?(Array)
           Shellwords.shelljoin default
@@ -41,7 +49,7 @@ def name
       end
 
       def usage_string(extended: false)
-        result = [aliases.join(', ')]
+        result = [usage_aliases.join(', ')]
         result << arg.upcase if arg
         result << strings[:required] if required && extended
         result << strings[:repeatable] if repeatable && extended
@@ -53,6 +61,18 @@ def usage_string(extended: false)
       def primary_aliases
         [long, short].compact
       end
+
+      def usage_aliases
+        [usage_long, short].compact + alt
+      end
+
+      def usage_long
+        negatable && long ? "--[no-]#{long_without_prefix}" : long
+      end
+
+      def long_without_prefix
+        long.delete_prefix '--'
+      end
     end
   end
 end
diff --git a/lib/bashly/views/flag/argfile_case.gtx b/lib/bashly/views/flag/argfile_case.gtx
index 89cf0f2a..f446f0f8 100644
--- a/lib/bashly/views/flag/argfile_case.gtx
+++ b/lib/bashly/views/flag/argfile_case.gtx
@@ -1,6 +1,13 @@
 = view_marker
 
-> {{ aliases.join " | " }})
+> {{ positive_aliases.join " | " }})
 = render(arg ? :argfile_case_arg : :argfile_case_no_arg).indent 2
 >   ;;
 >
+
+if negatable
+  > {{ negated_long }})
+  >   unset "args[{{ name }}]"
+  >   ;;
+  >
+end
diff --git a/lib/bashly/views/flag/case.gtx b/lib/bashly/views/flag/case.gtx
index bdab88a8..a4166518 100644
--- a/lib/bashly/views/flag/case.gtx
+++ b/lib/bashly/views/flag/case.gtx
@@ -1,6 +1,14 @@
 = view_marker
 
-> {{ aliases.join " | " }})
+> {{ positive_aliases.join " | " }})
 = render(:conflicts).indent 2
 = render(arg ? :case_arg : :case_no_arg).indent 2
 >
+
+if negatable
+  > {{ negated_long }})
+  >   unset "args[{{ name }}]"
+  >   shift
+  >   ;;
+  >
+end
diff --git a/schemas/bashly.json b/schemas/bashly.json
index fef4250e..340d4557 100644
--- a/schemas/bashly.json
+++ b/schemas/bashly.json
@@ -290,6 +290,12 @@
             ]
           }
         },
+        "negatable": {
+          "title": "negatable",
+          "description": "Whether the current flag also accepts its --no- form\nhttps://bashly.dev/configuration/flag/#negatable",
+          "type": "boolean",
+          "default": false
+        },
         "completions": {
           "title": "completions",
           "description": "Completions of the current flag\nhttps://bashly.dev/configuration/flag/#completions",
diff --git a/spec/approvals/cli/doc/full b/spec/approvals/cli/doc/full
index eb4baebc..462a70aa 100644
--- a/spec/approvals/cli/doc/full
+++ b/spec/approvals/cli/doc/full
@@ -784,6 +784,17 @@ flag.needs
 
   See https://bashly.dev/configuration/flag/#needs
 
+flag.negatable
+
+  Allow a boolean long flag to also be disabled with its --no- form.
+
+    flags:
+    - long: --color
+      help: Enable color output
+      negatable: true
+
+  See https://bashly.dev/configuration/flag/#negatable
+
 flag.private
 
   Specify that this flag should not be displayed in the help text.
diff --git a/spec/approvals/cli/doc/index b/spec/approvals/cli/doc/index
index d381f3a9..2e744849 100644
--- a/spec/approvals/cli/doc/index
+++ b/spec/approvals/cli/doc/index
@@ -48,6 +48,7 @@ flag.default
 flag.help
 flag.long
 flag.needs
+flag.negatable
 flag.private
 flag.repeatable
 flag.required
diff --git a/spec/approvals/fixtures/negatable-argfile b/spec/approvals/fixtures/negatable-argfile
new file mode 100644
index 00000000..6ef969b2
--- /dev/null
+++ b/spec/approvals/fixtures/negatable-argfile
@@ -0,0 +1,32 @@
+creating user files in src
+created src/root_command.sh
+created ./colorize
+run ./colorize --help to test your bash script
++ ./colorize
+# This file is located at 'src/root_command.sh'.
+# It contains the implementation for the 'colorize' command.
+# The code you write here will be wrapped by a function named 'root_command()'.
+# Feel free to edit this file; your changes will persist when regenerating.
+args:
+- ${args[--color]} = 1
++ ./colorize --no-color
+# This file is located at 'src/root_command.sh'.
+# It contains the implementation for the 'colorize' command.
+# The code you write here will be wrapped by a function named 'root_command()'.
+# Feel free to edit this file; your changes will persist when regenerating.
+args: none
++ ARGFILE=.colorize-off
++ ./colorize
+# This file is located at 'src/root_command.sh'.
+# It contains the implementation for the 'colorize' command.
+# The code you write here will be wrapped by a function named 'root_command()'.
+# Feel free to edit this file; your changes will persist when regenerating.
+args: none
++ ARGFILE=.colorize-off
++ ./colorize --color
+# This file is located at 'src/root_command.sh'.
+# It contains the implementation for the 'colorize' command.
+# The code you write here will be wrapped by a function named 'root_command()'.
+# Feel free to edit this file; your changes will persist when regenerating.
+args:
+- ${args[--color]} = 1
diff --git a/spec/approvals/validations/flag_negatable_type b/spec/approvals/validations/flag_negatable_type
new file mode 100644
index 00000000..efc1114d
--- /dev/null
+++ b/spec/approvals/validations/flag_negatable_type
@@ -0,0 +1 @@
+#<Bashly::ConfigurationError: root.flags[0].negatable must be a boolean>
\ No newline at end of file
diff --git a/spec/approvals/validations/flag_negatable_with_arg b/spec/approvals/validations/flag_negatable_with_arg
new file mode 100644
index 00000000..c94de58f
--- /dev/null
+++ b/spec/approvals/validations/flag_negatable_with_arg
@@ -0,0 +1 @@
+#<Bashly::ConfigurationError: root.flags[0].negatable does not make sense with nub`arg`>
\ No newline at end of file
diff --git a/spec/approvals/validations/flag_negatable_with_repeatable b/spec/approvals/validations/flag_negatable_with_repeatable
new file mode 100644
index 00000000..9958df53
--- /dev/null
+++ b/spec/approvals/validations/flag_negatable_with_repeatable
@@ -0,0 +1 @@
+#<Bashly::ConfigurationError: root.flags[0].negatable does not make sense with nub`repeatable`>
\ No newline at end of file
diff --git a/spec/approvals/validations/flag_negatable_with_required b/spec/approvals/validations/flag_negatable_with_required
new file mode 100644
index 00000000..a6bc534c
--- /dev/null
+++ b/spec/approvals/validations/flag_negatable_with_required
@@ -0,0 +1 @@
+#<Bashly::ConfigurationError: root.flags[0].negatable does not make sense with nub`required`>
\ No newline at end of file
diff --git a/spec/approvals/validations/flag_negatable_without_long b/spec/approvals/validations/flag_negatable_without_long
new file mode 100644
index 00000000..64fb9281
--- /dev/null
+++ b/spec/approvals/validations/flag_negatable_without_long
@@ -0,0 +1 @@
+#<Bashly::ConfigurationError: root.flags[0].negatable requires nub`long`>
\ No newline at end of file
diff --git a/spec/approvals/validations/non_uniq_flags_negatable b/spec/approvals/validations/non_uniq_flags_negatable
new file mode 100644
index 00000000..662734da
--- /dev/null
+++ b/spec/approvals/validations/non_uniq_flags_negatable
@@ -0,0 +1 @@
+#<Bashly::ConfigurationError: root.flags contains non-unique elements (--no-color) in long or short or alias>
\ No newline at end of file
diff --git a/spec/bashly/completion_builder_spec.rb b/spec/bashly/completion_builder_spec.rb
index c66a255a..ff0f7d10 100644
--- a/spec/bashly/completion_builder_spec.rb
+++ b/spec/bashly/completion_builder_spec.rb
@@ -30,4 +30,21 @@
       expect(data['tokens']['get_package']).to eq %w[hello world]
     end
   end
+
+  context 'with a negatable flag' do
+    let(:command) do
+      Script::Command.new(
+        'name'  => 'cli',
+        'flags' => [
+          { 'long' => '--color', 'short' => '-c', 'negatable' => true },
+        ]
+      )
+    end
+
+    it 'adds the negated long option to the same option entry' do
+      data = described_class.new(command).call
+
+      expect(data['options']['root']).to include '--color|--no-color|-c'
+    end
+  end
 end
diff --git a/spec/bashly/script/flag_spec.rb b/spec/bashly/script/flag_spec.rb
index 100ca4f1..07b319cc 100644
--- a/spec/bashly/script/flag_spec.rb
+++ b/spec/bashly/script/flag_spec.rb
@@ -54,6 +54,14 @@
         expect(subject.aliases).to eq ['--container', '--pod']
       end
     end
+
+    context 'with a negatable flag' do
+      let(:fixture) { :negatable }
+
+      it 'includes the negated long option' do
+        expect(subject.aliases).to eq ['--color', '--no-color', '-c']
+      end
+    end
   end
 
   describe '#default_string' do
@@ -119,6 +127,14 @@
       end
     end
 
+    context 'with a negatable flag' do
+      let(:fixture) { :negatable_with_alias }
+
+      it 'uses bracket notation for the negated long option' do
+        expect(subject.usage_string).to eq '--[no-]color, -c, --colour'
+      end
+    end
+
     context 'with extended: true' do
       context 'when the flag is optional' do
         it 'returns the same string as it does without extended' do
@@ -155,5 +171,18 @@
         expect(result).to include "args['--container']=\"$2\""
       end
     end
+
+    context 'with a negatable flag' do
+      let(:fixture) { :negatable }
+
+      it 'assigns and unsets the canonical flag name' do
+        result = subject.render(:case)
+
+        expect(result).to include '--color | -c)'
+        expect(result).to include "args['--color']=1"
+        expect(result).to include '--no-color)'
+        expect(result).to include 'unset "args[--color]"'
+      end
+    end
   end
 end
diff --git a/spec/fixtures/script/flags.yml b/spec/fixtures/script/flags.yml
index 4c8a831f..dbea438b 100644
--- a/spec/fixtures/script/flags.yml
+++ b/spec/fixtures/script/flags.yml
@@ -13,6 +13,17 @@
   long: --container
   alias: --pod
 
+:negatable:
+  long: --color
+  short: -c
+  negatable: true
+
+:negatable_with_alias:
+  long: --color
+  short: -c
+  alias: --colour
+  negatable: true
+
 :long_only:
   long: --long
 
diff --git a/spec/fixtures/script/validations.yml b/spec/fixtures/script/validations.yml
index 6a6bb818..cfbfae2e 100644
--- a/spec/fixtures/script/validations.yml
+++ b/spec/fixtures/script/validations.yml
@@ -344,6 +344,44 @@
   flags:
   - long: force
 
+:flag_negatable_type:
+  name: invalid
+  help: flag.negatable should be boolean
+  flags:
+  - long: --color
+    negatable: maybe
+
+:flag_negatable_without_long:
+  name: invalid
+  help: flag.negatable requires long
+  flags:
+  - short: -c
+    negatable: true
+
+:flag_negatable_with_arg:
+  name: invalid
+  help: flag.negatable cannot be used with arg
+  flags:
+  - long: --color
+    arg: mode
+    negatable: true
+
+:flag_negatable_with_repeatable:
+  name: invalid
+  help: flag.negatable cannot be used with repeatable
+  flags:
+  - long: --color
+    repeatable: true
+    negatable: true
+
+:flag_negatable_with_required:
+  name: invalid
+  help: flag.negatable cannot be used with required
+  flags:
+  - long: --color
+    required: true
+    negatable: true
+
 :flag_required_and_default:
   name: invalid
   help: flag cannot have both required and default
@@ -449,6 +487,14 @@
     alias: [--pod, -p]
   - long: --podman
     short: -p
+
+:non_uniq_flags_negatable:
+  name: invalid
+  help: generated negatable flag conflicts with another flag
+  flags:
+  - long: --color
+    negatable: true
+  - long: --no-color
   
 :non_uniq_arg_names:
   name: invalid
diff --git a/spec/fixtures/workspaces/negatable-argfile/.colorize b/spec/fixtures/workspaces/negatable-argfile/.colorize
new file mode 100644
index 00000000..4e1e0d2f
--- /dev/null
+++ b/spec/fixtures/workspaces/negatable-argfile/.colorize
@@ -0,0 +1 @@
+--color
diff --git a/spec/fixtures/workspaces/negatable-argfile/.colorize-off b/spec/fixtures/workspaces/negatable-argfile/.colorize-off
new file mode 100644
index 00000000..04bc1ca1
--- /dev/null
+++ b/spec/fixtures/workspaces/negatable-argfile/.colorize-off
@@ -0,0 +1,2 @@
+--color
+--no-color
diff --git a/spec/fixtures/workspaces/negatable-argfile/.gitignore b/spec/fixtures/workspaces/negatable-argfile/.gitignore
new file mode 100644
index 00000000..77f1efc1
--- /dev/null
+++ b/spec/fixtures/workspaces/negatable-argfile/.gitignore
@@ -0,0 +1 @@
+/colorize
diff --git a/spec/fixtures/workspaces/negatable-argfile/src/bashly.yml b/spec/fixtures/workspaces/negatable-argfile/src/bashly.yml
new file mode 100644
index 00000000..b472aab7
--- /dev/null
+++ b/spec/fixtures/workspaces/negatable-argfile/src/bashly.yml
@@ -0,0 +1,11 @@
+name: colorize
+help: Test negatable argfile behavior
+version: 0.1.0
+
+argfile: .colorize
+
+flags:
+- long: --color
+  short: -c
+  help: Enable color output
+  negatable: true
diff --git a/spec/fixtures/workspaces/negatable-argfile/src/root_command.sh b/spec/fixtures/workspaces/negatable-argfile/src/root_command.sh
new file mode 100644
index 00000000..f77da0ae
--- /dev/null
+++ b/spec/fixtures/workspaces/negatable-argfile/src/root_command.sh
@@ -0,0 +1,5 @@
+echo "# This file is located at 'src/root_command.sh'."
+echo "# It contains the implementation for the 'colorize' command."
+echo "# The code you write here will be wrapped by a function named 'root_command()'."
+echo "# Feel free to edit this file; your changes will persist when regenerating."
+inspect_args
diff --git a/spec/fixtures/workspaces/negatable-argfile/test.sh b/spec/fixtures/workspaces/negatable-argfile/test.sh
new file mode 100644
index 00000000..53a9f534
--- /dev/null
+++ b/spec/fixtures/workspaces/negatable-argfile/test.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+rm -f ./colorize
+rm -f ./src/*.sh
+
+bundle exec bashly generate
+
+set -x
+
+./colorize
+./colorize --no-color
+ARGFILE=.colorize-off ./colorize
+ARGFILE=.colorize-off ./colorize --color
diff --git a/support/schema/bashly.yml b/support/schema/bashly.yml
index ccc130f8..166471ee 100644
--- a/support/schema/bashly.yml
+++ b/support/schema/bashly.yml
@@ -247,6 +247,13 @@ definitions:
           minLength: 1
           examples:
             - --command
+      negatable:
+        title: negatable
+        description: |-
+          Whether the current flag also accepts its --no- form
+          https://bashly.dev/configuration/flag/#negatable
+        type: boolean
+        default: false
       completions:
         title: completions
         description: |-