diff --git a/package.json b/package.json
index b1e81d7cc..161b24151 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@oclif/core",
   "description": "base library for oclif CLIs",
-  "version": "4.5.5",
+  "version": "4.5.6-autocomplete.0",
   "author": "Salesforce",
   "bugs": "https://github.com/oclif/core/issues",
   "dependencies": {
diff --git a/src/interfaces/index.ts b/src/interfaces/index.ts
index 4b49296e9..2c6261f07 100644
--- a/src/interfaces/index.ts
+++ b/src/interfaces/index.ts
@@ -12,6 +12,7 @@ export type {
   ArgDefinition,
   ArgInput,
   BooleanFlag,
+  Completion,
   CustomOptions,
   Deprecation,
   Flag,
diff --git a/src/interfaces/parser.ts b/src/interfaces/parser.ts
index f88a56683..02bec2038 100644
--- a/src/interfaces/parser.ts
+++ b/src/interfaces/parser.ts
@@ -231,6 +231,21 @@ export type OptionFlagProps = FlagProps & {
    * Should only be used on one flag at a time.
    */
   allowStdin?: boolean | 'only'
+  /**
+   * Optional dynamic completion configuration.
+   * Provides intelligent autocomplete suggestions for flag values based on context.
+   * Requires autocomplete plugin to be installed.
+   *
+   * @example
+   * ```typescript
+   * completion: {
+   *   options: async (ctx) => {
+   *     return ['option1', 'option2', 'option3']
+   *   }
+   * }
+   * ```
+   */
+  completion?: Completion
 }
 
 export type FlagParserContext = Command & {token: FlagToken}
@@ -439,6 +454,33 @@ export type ParserInput = {
   '--'?: boolean | undefined
 }
 
+/**
+ * Completion configuration for a flag
+ */
+export type Completion = {
+  /**
+   * Function that returns completion options
+   *
+   * @returns Promise resolving to array of completion strings
+   *
+   * @example
+   * ```typescript
+   * static flags = {
+   *   'target-org': Flags.string({
+   *     description: 'Target org',
+   *     completion: {
+   *       options: async () => {
+   *         const orgs = await getAuthenticatedOrgs()
+   *         return orgs.map(o => o.alias)
+   *       }
+   *     }
+   *   })
+   * }
+   * ```
+   */
+  options(): Promise<string[]>
+}
+
 export type ParserContext = Command & {
   token?: FlagToken | ArgToken | undefined
 }
diff --git a/test/interfaces/parser.test.ts b/test/interfaces/parser.test.ts
new file mode 100644
index 000000000..5b9149580
--- /dev/null
+++ b/test/interfaces/parser.test.ts
@@ -0,0 +1,29 @@
+import {expect} from 'chai'
+
+import * as Interfaces from '../../src/interfaces'
+
+describe('Completion types', () => {
+  it('allows completion property on OptionFlag', () => {
+    const completion: Interfaces.Completion = {
+      async options() {
+        return ['option1', 'option2']
+      },
+    }
+
+    expect(completion).to.exist
+    expect(completion.options).to.be.a('function')
+  })
+
+  it('completion function returns promise of strings', async () => {
+    const completion: Interfaces.Completion = {
+      async options() {
+        return ['a', 'b', 'c']
+      },
+    }
+
+    const result = await completion.options()
+
+    expect(result).to.be.an('array')
+    expect(result).to.deep.equal(['a', 'b', 'c'])
+  })
+})