Paul Marshall Guest OAM, (born 8 March 1939) is an Australian rower, a family law barrister and Queen's Counsel who spent ten years as a judge on the bench of the Family Court of Australia.
As a rower, he was a six-time Australian national champion, raced in nine King's Cup eights for Victoria over a 15-year period, and competed at three Olympic Games.
As a Family Court justice, Guest's pivotal ruling in the "Re Patrick" case dealt with the complex area of known sperm donor's rights under the Family Law Act.
Guest is a collector and benefactor of contemporary art whose personal collection has been lent for display to a number of prominent Australian galleries.