Karch Kiraly is considered one of the greatest American male volleyball players ever. He won a total of three Olympic gold medals, including one in beach volleyball in 1996.
Kelly Clark is considered one of the greatest female snowboarders in history. She won one gold and two bronze medals at the Olympics along with seven gold medals at the Winter X Games.
Kenny Smith played in the NBA from 1987-97 and enjoyed most of his success with the Houston Rockets, winning two titles. He's currently an NBA analyst on TNT.
Kerri Walsh Jennings is the most decorated female beach volleyball player of all-time, winning three Olympic gold medals and one bronze medal over the course of four Summer Games.
Kevin Youkilis played in the majors from 2004-2013 and enjoyed most of his success with the Boston Red Sox, where he won two World Series. He was named an All-Star three times and won a Gold Glove in 2007.
Keyshawn Johnson is a retired wide receiver who was a three-time Pro Bowler and played from 1996-2006 for the New York Jets, Tampa Bay Buccaneers, Dallas Cowboys and Carolina Panthers.
Kurt Rambis played in the NBA from 1981 - 95 and enjoyed most of his success with the Los Angeles Lakers, winning four NBA titles as a player and three as an assistant coach.