Kerwin Joseph Danley (born May 25, 1961) is an umpire in Major League Baseball who has worked in the National League (NL) from 1992 to 1999 and throughout both leagues since 2000. Danley has worked the American League Division Series six times (2000, 2001, 2004, 2006, 2008, 2011). He also umpired in the 2007 and 2016 Major League Baseball All-Star Games. Kerwin is married to Marisa Danley.
Danley played baseball at San Diego State University, where he was teammates with Bud Black and future Hall of Famer Tony Gwynn, before beginning his umpiring career. He was a First Team All-American in 1983.
Danley was the first base umpire for the game between the San Francisco Giants and the San Diego Padres on August 4, 2007. In the top of the second inning at San Diego, Barry Bonds of the Giants hit his 755th career home run off Clay Hensley, tying Hank Aaron for first all-time.
Danley was on the field on August 6, 1999 when former San Diego State teammate Tony Gwynn collected his 3,000th career hit.
Danley has received a few injuries while umpiring. In 2008, he was hit in the jaw by a 96 mph fastball. A year later Hank Blalock's bat broke with part of it hitting Danley in the facemask. He was carried off the field on a stretcher for the 2nd time in his career. In 2012, Danley was struck by the baseball directly in the groin. He fell to the ground, but remained in the game. In 2013, Danley was hit on his face mask by a pitch that bounced in the dirt and off the catcher. He remained in the game until the decision was made for him to leave the game at the top of the third. In 2015, he was again hit by a pitch between the eyes on his face mask and had to leave the game. While umpiring home plate at Dodger Stadium in 2017, he took a Cody Bellinger foul ball off his face mask and had to leave the game.
Danley was the first base umpire for Miami Marlins pitcher Edinson Vólquez's no-hitter against the Arizona Diamondbacks on June 3, 2017.