Mark William Seymour (1897 – 16 September 1952) was an English professional golfer. His birth was registered as William Mark Seymour. He was a half-brother of Abe Mitchell. Although not as successful as his half-brother, he enjoyed considerable success during his time in Scotland and twice played for England against Scotland. In important tournaments he was a runner-up in the 1931 Irish Open and a losing finalist in the 1931 and 1933 News of the World Match Play.