Seth Tyler Simmons (born June 14, 1988) is an American professional baseball pitcher who is a free agent.

[3] The Arizona Diamondbacks selected Simmons in the 40th round of the 2011 Major League Baseball draft.

[6] Simmons split the 2018 season between Double–A San Antonio and the Triple–A El Paso Chihuahuas, making 18 appearances and accumulating a 3.81 ERA with 36 strikeouts across 54+1⁄3 innings pitched.

[7] In early 2019, Simmons signed with the High Point Rockers of the Atlantic League of Professional Baseball.

On July 12, 2019, Simmons was traded to the Long Island Ducks of the Atlantic League of Professional Baseball.