Clarke MacArthur (born April 6, 1985) is a Canadian professional ice hockey left winger currently playing for the Toronto Maple Leafs of the National Hockey League (NHL). He was drafted by the Sabres in the third round (74th overall) of the 2003 NHL Entry Draft. MacArthur started his NHL career with the Buffalo Sabres, and was later traded to the Atlanta Thrashers. He played with the Sabres American Hockey League (AHL) affiliate Rochester Americans while trying to make the NHL. Before turning professional, MacArthur spent three seasons playing for the Medicine Hat Tigers in the Western Hockey League (WHL). While playing junior hockey, he was named to the 2004 Memorial Cup All-Star and 2005 WHL Eastern Conference All-Star Teams. He was also a member of Canada's gold-medal-winning squad at the 2005 World Junior Championships.
MacArthur played minor hockey in his hometown of Lloydminster, Alberta. He went unselected in the Western Hockey League (WHL) Bantam Draft when he was eligible, due in part to his short stature. While playing bantam hockey in Alberta, MacArthur put up impressive statistics, despite standing only 5'4". He recorded 99 points in 38 games during the 2000–01 season with the Strathcona Warriors. After the season, he was named his club's most valuable player.
With the numbers MacArthur put up in bantam hockey, he was able to secure a tryout with the Medicine Hat Tigers, but was the club's final cut heading into the 2001–02 season. As a result, MacArthur played in the Alberta Junior Hockey League (AJHL) for the Drayton Valley Thunder. In his only season in the AJHL, MacArthur recorded 62 points in 62 games, and helped the Thunder capture a league championship. During the season he grew seven inches and the Medicine Hat Tigers were again interested in his services. He joined the club for the 2002–03 season, putting up 75 points in 70 games as a WHL rookie. During the summer, MacArthur was drafted by the Buffalo Sabres in the third round (75th overall) of the 2003 NHL Entry Draft.