Matheu Adam Nelson (born January 14, 1999) is an American professional baseball catcher in the Cincinnati Reds organization.

Nelson grew up in Largo, Florida and attended Calvary Christian High School, where one of his coaches was Hall of Fame pitcher Roy Halladay until his death.

[2] Nelson was selected in the 39th round of the 2018 Major League Baseball draft by the Philadelphia Phillies, but opted not to sign with the team.

[6][7] As a junior in 2021, he started 53 of the Seminoles games and was named the Atlantic Coast Conference Baseball Player of the Year after batting .330 with 17 doubles and a conference-leading 23 home runs.

[15] He made his professional debut with the Rookie-level Arizona Complex League Reds and was later promoted to the Dayton Dragons of the High-A Central.