Mark Andrew Mathias (born August 2, 1994) is an American professional baseball second baseman who is a free agent.

He has previously played in Major League Baseball (MLB) for the Milwaukee Brewers, Texas Rangers, Pittsburgh Pirates, and San Francisco Giants.

[1] He played shortstop and pitched, and was MVP and first-team All-Mission Valley League in his junior year.

[2] Undrafted out of high school, Mathias attended California Polytechnic State University, San Luis Obispo, where he played college baseball for the Cal Poly Mustangs.

He split the 2016 season between the Lynchburg Hillcats and the Akron RubberDucks, hitting a combined .267/.351/.396 with five home runs and 61 RBIs.

[13] On March 16, 2021, Mathias was placed on the 60-day injured list due to a torn labrum in his shoulder, and remained there through the end of the season.

[6] On June 11, Mathias hit his first major league home run, a two-run shot off of Patrick Corbin of the Washington Nationals.

[19] On March 4, 2023, Mathias was designated for assignment by the Rangers after the signing of Will Smith was made official.

[6] On July 31, 2023, Mathias and A. J. Pollock were traded to the San Francisco Giants in exchange for cash considerations or a player to be named later.