Scott William Mathieson (born February 27, 1984 in Vancouver, British Columbia, Canada) is a Philadelphia Phillies pitching prospect.

Mathieson was drafted in the 17th round of the Major League Baseball Draft -- 509th overall -- by the Phillies. He made his professional debut in the Gulf Coast League (GCL), going 0-2 with an earned run average of 5.40 in seven games. In , he went 2-7 with a 5.52 ERA in the GCL. That year, he also pitched six perfect innings in one game for the Batavia Muckdogs of the New York-Penn League, including 7 strikeouts. In , he pitched for the Lakewood BlueClaws of the South Atlantic League, going 8-9 with an ERA of 4.32 and 112 strikeouts. In , he continued to show improvement. Although he went 3-8 for the Clearwater Threshers of the FSL, he had an ERA of 4.14, 118 strikeouts, and only 34 walks in 121 2/3 innings. During the season, he also pitched in the All-Star Futures Game for the World team. After the season, he was named by Baseball America as the Phillies' fourth-best prospect and the organization's best right-handed pitching prospect.

Mathieson made his Major League debut June 17, , losing to the Tampa Bay Devil Rays, 7-2. Matheison suffered an elbow injury September 2 that required Tommy John surgery.

Mathieson began a rehabilitation program late in the season, but removed himself from a game August 31 while pitching for Double-A Reading when he felt "a strange sensation in his elbow." The Phillies announced September 4 that Mathieson would not return during 2007 due to inflammation of the ulnar nerve. Mathieson was scheduled to play in the 2007 Arizona Fall League with the Peoria Saguaros, but didn't.