Stephen Peyser (born July 28, 1986, in Lloyd Harbor, New York) is an American professional lacrosse player with the Long Island Lizards of Major League Lacrosse. Peyser also played with the Orlando Titans and New York Titans of the National Lacrosse League. He plays the midfield position.

Peyser won two national championships while playing with the Johns Hopkins Blue Jays. As a freshman, he played in all sixteen games and helped the Blue Jays win the 2005 NCAA Division I Men's Lacrosse Championship. In 2006, Peyser missed a significant part of the season due to a broken jaw suffered prior to the season. In his junior season he was awarded USILA third team All-American honors, and again helped his team win the national championship. Peyser was named to the 2007 NCAA Division I Men's Lacrosse Championship All-tournament team for his efforts in the tournament.^[1] As a senior, Peyser and the Blue Jays were again in the national championship game; however, this time they were defeated by the Syracuse Orange.

As collegiate lacrosse has developed more specialists, Peyser's abilities as both a face-off man and offensive and defensive midfielder contributed to the Blue Jays success during his collegiate career.

Peyser began his professional career with the New Jersey Pride in 2008. The Pride drafted Peyser 5th overall in the first round of the 2008 MLL Collegiate Draft.^[2][3] Peyser joined the New Jersey Pride which already featured his two older brothers, Michael and Gregory. During Week 6 of the 2008 MLL season, the Peyser brothers (Michael, Gregory, and Stephen) became the first trio of brothers to play on the same Major League Lacrosse team together.^[4]

Peyser has had an immediate impact on the league, and was named Rookie of the Week for Week 11 of the 2008 season.^[5]

He also joined his brother Greg as a member of the indoor lacrosse 2009 New York Titans. During the season, he was named to the All-Star Game as an injury replacement.^[6]