Launched in January 2025 to mark 50 years since the merger of George Watson's Ladies' College and George Watson's Boys' College, the tartan was designed and gifted to the school by Edinburgh Highland dress specialists Kinloch Anderson.

It takes its lead from the Buchanan tartan, the clan of which the Watsons were a sept. The colours come from elements of school life, and a red overcheck carries the motto, Love from the heart. The thread count itself holds the school's history.