Joshua Michael Collmenter (born February 7, 1986) is an American former professional baseball pitcher who played in Major League Baseball (MLB) for the Arizona Diamondbacks and Atlanta Braves between 2011 and 2017, and currently acts as the color man for Diamondbacks Radio. He attended Central Michigan University and was the 2007 Mid-American Conference Pitcher of the Year.

Joshua Michael Collmenter was born on February 7, 1986, in rural Homer, Michigan, where he grew up. He learned to pitch by watching baseball on television and reading about how to grip different pitches in Sports Illustrated. His pitching mechanics, however, are the product of a childhood spent with his brothers entertaining themselves by throwing tomahawks at things such as snakes and trees. The process resulted in the development of an unorthodox, extremely overhand pitching motion.

Collmenter attended Homer High School, where he played baseball, basketball and football and graduated as the salutatorian of his class in 2004. Collmenter was one of the top pitchers in Michigan high school baseball history. In 2004, Collmenter led the Trojans to a 38–0 record and the first undefeated championship season in the state's history. That season propelled the Trojans to a national-record 75 game win streak. Collmenter won 18 games in the 2004 season, the third highest total in state history. He recorded a state-record 13 shutouts that season while striking out 223 batters and notching a 0.13 ERA. Collmenter finished his high school career with 49 wins, 23 shutouts, 546 strikeouts and a 0.99 ERA, all of which rank in the top six in state history. Homer compiled a record of 110–18 while Collmenter was with the team.

Prior to playing professionally, Collmenter attended Central Michigan University, with whom he played from 2005 to 2007. In his first season with the Chippewas, Collmenter went 7–1 with a 2.70 ERA in 16 games (10 starts). The following season, Collmenter went 8–5 with a 3.41 ERA in 15 games (14 starts). In 2006, he played collegiate summer baseball with the Hyannis Mets of the Cape Cod Baseball League. He went 9–4 with a 1.93 ERA in 15 starts in 2007. He was named the 2007 Mid-American Conference Baseball Pitcher of the Year.

Collmenter was drafted in the 15th round (463rd overall) of the 2007 Major League Baseball draft by the Arizona Diamondbacks. He started his professional career that year, playing for the Yakima Bears in 2007, going 6–3 with a 2.71 ERA in 14 games (12 starts). In 2008, Collmenter pitched for the South Bend Silver Hawks, going 12–8 with a 3.41 ERA in 27 starts. He was a well-known figure that season for growing a mustache in the hope of turning the Silver Hawks fortunes around.

The following season, Collmenter went 8–10 with a 4.15 ERA in 27 starts for the Visalia Rawhide. As well, he struck out 152 batters in 1451⁄3 innings that season. He split the 2010 season between the Rawhide, Mobile Bay Bears and Reno Aces, going a combined 14–8 with a 3.38 ERA in 25 starts.

Collmenter made his major league debut on April 17, 2011, against the San Francisco Giants. Collmenter entered the game in the 11th inning of a 5–5 game. He pitched two perfect innings with two strikeouts. The Diamondbacks would go on to win the game in the bottom of the 12th when Stephen Drew drove in Justin Upton for the game's winning run, cementing Collmenter's first big league win.

Collmenter caught the eye of some observers due to his unusual over-the-top delivery. It was thought that the deceptiveness of the delivery attributed to much of his success. He was the first pitcher since earned runs were recorded in 1912 to have given up four or fewer total earned runs and 20 or fewer total hits in his first six starts. Although Collmenter didn't possess superior velocity to his fastball (average 87 MPH), he relied on throwing a sizable amount of cutters and changeups to keep hitters off-balance. He also threw a curveball less frequently.