In the late 1940s, Thomson turned pro and had much success on the Australasian circuits, culminating with a win at the 1951 Australian Open.

He decided to focus on Europe thereafter with extraordinary success, winning dozens of tournaments on the British PGA, including the Open Championship five times.

Thomson was a prolific tournament champion around the world, winning the national championships of ten countries, including the New Zealand Open nine times.

In the era, that Thomson won his first four Open Championships, few of the leading professionals from the United States travelled to Britain to play in that event.

In 1985 he won nine times on the Senior PGA Tour in the United States, and finished top of the money list.

[4][5] PGA Tour playoff record (2–0) *Note: The 1976 Pepsi-Wilson Tournament was shortened to 54 holes due to rain.