Marty Reasoner, (born February 26, 1977 in Honeoye Falls, New York) is an American professional ice hockey center currently playing for the Atlanta Thrashers of the National Hockey League (NHL). He has also played for the St. Louis Blues, Edmonton Oilers and Boston Bruins.

He was selected in the first round of the 1996 NHL Entry Draft, 14th overall, by the St. Louis Blues. This followed two years of high school hockey at McQuaid Jesuit High School, two years of high school at Deerfield Academy in Massachusetts and three years at Boston College, where he was named Rookie of the Year his freshmen year, and named All-American his junior season when he led the Eagles to the NCAA finals. He skated alongside the BC legends Andy Powers and Brian Gionta. Reasoner split 1998–2001 between the Blues and their top minor-league affiliate, the Worcester IceCats. In 2003, he was voted a starter on the IceCats' tenth-anniversary All-Time Team.

Reasoner was traded on July 1, 2001 to the Edmonton Oilers, along with Jochen Hecht and Jan Horáček in exchange for Oilers' captain Doug Weight and Michel Riesen. In November 2003, Reasoner suffered a severe knee injury when he crashed into the end boards. During the 2004–05 NHL lockout, Reasoner played 11 games for EC Red Bull Salzburg of the Austrian League. On August 9, 2005, Reasoner and the Oilers came to terms on a one-year deal. He was traded from Edmonton to the Boston Bruins on March 9, 2006, along with Yan Stastny and a second-round pick in the 2006 NHL Entry Draft (Milan Lučić) in exchange for Sergei Samsonov, thus missing the incredible playoff run of the Oilers that year.