Cory Steven Blaser (born December 8, 1981) is an American Major League Baseball umpire.

Blaser is a graduate of Pomona High School and attended Colorado State University.

[1] Blaser attended the Harry Wendelstedt Umpire School, and works as an instructor there in the off-season.

[1] Blaser was officially named to the full-time MLB staff prior to the 2014 season.

Blaser worked his first career MLB postseason game in right field on October 7, 2015, serving in the 2015 National League Wild Card Game between the Chicago Cubs and the Pittsburgh Pirates.