diff --git a/projects/plugins/jetpack/changelog/fix-write-brief-spellcheck-numbers b/projects/plugins/jetpack/changelog/fix-write-brief-spellcheck-numbers
new file mode 100644
index 0000000000000..28a48a83cba5d
--- /dev/null
+++ b/projects/plugins/jetpack/changelog/fix-write-brief-spellcheck-numbers
@@ -0,0 +1,4 @@
+Significance: patch
+Type: other
+
+AI Assistant: Write Brief should not flag words like '2nd' and '100th' as spelling errors.
diff --git a/projects/plugins/jetpack/extensions/plugins/ai-assistant-plugin/components/breve/features/spelling-mistakes/index.ts b/projects/plugins/jetpack/extensions/plugins/ai-assistant-plugin/components/breve/features/spelling-mistakes/index.ts
index 44e5ac13094a2..78ce2847dcb0c 100644
--- a/projects/plugins/jetpack/extensions/plugins/ai-assistant-plugin/components/breve/features/spelling-mistakes/index.ts
+++ b/projects/plugins/jetpack/extensions/plugins/ai-assistant-plugin/components/breve/features/spelling-mistakes/index.ts
@@ -185,9 +185,9 @@ export default function spellingMistakes( text: string ): Array< HighlightedText
 	// \p{M} matches any Unicode mark (combining characters)
 	// The regex has three main parts:
 	// 1. [@#+$/]{0,1} - Optionally matches a single special character at the start
-	// 2. [\p{L}\p{M}'-]+ - Matches one or more letters, marks, apostrophes, or hyphens
-	// 3. (?:\/[\p{L}\p{M}'-]+)* - Optionally matches additional parts separated by slashes
-	const wordRegex = new RegExp( /[@#+$/]{0,1}[\p{L}\p{M}'-]+(?:\/[\p{L}\p{M}'-]+)*/gu );
+	// 2. [\p{L}\p{M}\p{N}'-]+ - Matches one or more letters, marks, numbers, apostrophes, or hyphens
+	// 3. (?:\/[\p{L}\p{M}\p{N}'-]+)* - Optionally matches additional parts separated by slashes
+	const wordRegex = new RegExp( /[@#+$/]{0,1}[\p{L}\p{M}\p{N}'-]+(?:\/[\p{L}\p{M}\p{N}'-]+)*/gu );
 	const matches = Array.from( text.matchAll( wordRegex ) );
 
 	matches.forEach( match => {
@@ -199,6 +199,11 @@ export default function spellingMistakes( text: string ): Array< HighlightedText
 			return;
 		}
 
+		// Skip anything that is a valid number
+		if ( ! isNaN( Number( word ) ) ) {
+			return;
+		}
+
 		// Split words by hyphens and slashes
 		const subWords = word.split( /[-/]/ );