Kirk R. Carlsen (born May 25, 1987 in Nashua, New Hampshire) is an American former professional cyclist, who competed professionally between 2010 and 2014. He previously rode for Garmin–Transitions. He grew up in New Hampshire, and among his best results include several European victories with the U.S. National Team, U.S. U23 National Champion in 2008, and best climber at the Redlands Classic in 2009. Before Garmin, Carlsen rode for Garmin's development program, the U.S. National Team, Rubicon, and Peerless Insurance Junior Cycling Team.

Carlsen joined the Jelly Belly–Maxxis squad for the 2014 season, after his previous team – Bissell – folded at the end of the 2013 season. He retired after the 2014 season.