Trevor Michael Kelley was born on October 20, 1993, he is an American professional baseball pitcher for the Milwaukee Brewers of Major League Baseball (MLB). He is 6 feet 2 inches tall. He has previously played in MLB for the Boston Red Sox and Philadelphia Phillies.
In 2015, Kelley played for the rookie league GCL Red Sox and the Class A Short Season Lowell Spinners, combining to go 1–3 with a 3.60 ERA in 25 innings. He split the 2016 season between the Class A Greenville Drive and the Class A-Advanced Salem Red Sox, going a combined 1–3 with a 1.83 ERA in 39 innings.
He split 2017 between Salem and the Double-A Portland Sea Dogs, going a combined 2–1 with a 2.36 ERA over 60.1 innings. His 2018 season was split between Portland and the Triple-A Pawtucket Red Sox, going 2–3 with a 2.88 ERA in 56 innings.
On December 2, 2019, Kelley was claimed off waivers by the Philadelphia Phillies. He was designated for assignment by the Phillies on January 31, 2020, and outrighted on February 5. Kelley made the Opening Day roster for the Phillies in 2020.
He was designated for assignment again by the Phillies on August 11, 2020. He elected free agency on September 28, 2020. On December 21, 2020, Kelley signed a minor league contract with the Chicago Cubs.
On April 24, 2021, Kelley was released by the Cubs organization. On April 28, 2021, Kelley signed a minor league contract with the Atlanta Braves organization. Kelley spent the 2021 season with the Triple-A Gwinnett Stripers, making 37 appearances with a 1.52 ERA and 46 strikeouts.
Kelley became a free agent following the 2021 season. On November 18, 2021, Kelley signed a minor league deal with the Milwaukee Brewers, with an invitation to spring training.