diff --git a/apps/api-documenter/src/documenters/OfficeYamlDocumenter.ts b/apps/api-documenter/src/documenters/OfficeYamlDocumenter.ts
index 0050b7147ce..8c0aa44a30a 100644
--- a/apps/api-documenter/src/documenters/OfficeYamlDocumenter.ts
+++ b/apps/api-documenter/src/documenters/OfficeYamlDocumenter.ts
@@ -105,8 +105,10 @@ export class OfficeYamlDocumenter extends YamlDocumenter {
     //
     // Hyperlink it like this:
     // \[ [API set: ExcelApi 1.1](http://bing.com?type=excel) \]
-    markup = markup.replace(/Api/, 'API');
-    return markup.replace(/\\\[(API set:[^\]]+)\\\]/, '\\[ [$1](' + this._getApiSetUrl(uid) + ') \\]');
+    return markup.replace(
+      /\\\[[Aa][Pp][Ii] set:([^\]]+)\\\]/,
+      '\\[ [API set:$1](' + this._getApiSetUrl(uid) + ') \\]'
+    );
   }
 
   // Gets the link to the API set based on product context. Seeks a case-insensitive match in the hash set.
diff --git a/common/changes/@microsoft/api-documenter/AlexJ-APIDocumenterRegex_2025-06-20-17-45.json b/common/changes/@microsoft/api-documenter/AlexJ-APIDocumenterRegex_2025-06-20-17-45.json
new file mode 100644
index 00000000000..2c0fa3cccc7
--- /dev/null
+++ b/common/changes/@microsoft/api-documenter/AlexJ-APIDocumenterRegex_2025-06-20-17-45.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/api-documenter",
+      "comment": "Update regex in the OfficeYamlDocumenter to be case insensitive.",
+      "type": "patch"
+    }
+  ],
+  "packageName": "@microsoft/api-documenter"
+}
\ No newline at end of file