This article is about the baseball player. For the U.S. Representative see John R. Buck and for the artist see John E. Buck.

Johnathan Richard Buck (born July 7, 1980 in Kemmerer, Wyoming) is an American Major League Baseball player for the Kansas City Royals. He went to high school in Taylorsville, UT.

A catcher, Buck was initially drafted by the Houston Astros in the 7th round of the 1998 Amateur Draft. He was signed to a minor league contract on June 11, 1998.