Robert James Percival Marshall, OAM (10 April 1910 – 23 February 2004) was a noted Australian amateur player of English billiards.

He won the World Amateur Billiards Championship in 1936, 1938, 1951 and 1962 and was runner-up three times, as well as a national snooker champion.

Ten years later, the contemporary English snooker professional Fred Davis said of Marshall, "Most noticeable about his style is his compactness, so like Walter Lindrum, and the shortness of his back-swing, hardly more than a couple of inches.

"[1] Marshall dominated amateur billiards before and after the war with a career that spanned six decades, broken by retirements in 1963 and 1970 followed by come-backs.

[3] In 1969 he made a comeback for a series of exhibition matches against New Zealand professional Clark McConachy and regained his Australian title the same year, defending it successfully in 1970 before retiring once again.

Since his death at the age of 93, the memorial Bob Marshall Medal is awarded each year by the Australian Billiards & Snooker Council.