This led to parts in Bedelia, Hungry Hill and The Mark of Cain, and the beginning of Walsh's career in film.

Walsh made his first London stage appearance in George Bernard Shaw's Buoyant Billions at the Prince's Theatre in 1949.

He also played the title role in all 39 half-hour episodes of the series Richard the Lionheart in 1962 and 1963.

He married the actress Hazel Court in 1949, and the couple had a daughter, Sally (born 1950), before they were divorced in 1963.

He next married another actress, Diana Scougall, in 1968, and the couple had a son, Michael (born 1969), before they were divorced in 1974.