Mark Daniel Kolozsvary (/ˈkoʊloʊzvɑːriː/ KOH-lohz-var-ee;[1] born September 4, 1995) is an American professional baseball catcher in the Boston Red Sox organization.

[4] The Cincinnati Reds selected Kolozsvary in the seventh round, 197th overall, of the 2017 MLB draft,[2] and he signed with the team.

He was selected to the 40-man roster and made his major league debut on April 20, appearing as a defensive substitute for the Reds.

[11] On April 28, Kolozsvary collected his first MLB hit and RBI, lacing a double off of San Diego Padres starter and former Team USA teammate Nick Martinez.

[12] On July 23, Kolozsvary hit his first career home run, a solo shot off of Junior Fernández of the St. Louis Cardinals.

On June 13, 2023, Kolozsvary was selected to the major league roster after Ryan Mountcastle was placed on the injured list with vertigo.

[21] He played in 27 games for the Triple-A Worcester Red Sox in 2024, slashing .185/.349/.354 with three home runs, 10 RBI, and two stolen bases.