C
- "El Caballo" (Spanish, "The Horse") = Carlos Lee, Panamanian left fielder
- "Campy" =
- Roy Campanella, American catcher
- Bert Campaneris, Cuban shortstop
- "Candyman" =
- John Candelaria, American starting pitcher
- Tom Candiotti, American pitcher
- "Cap" = Adrian Anson, American first baseman
- "Captain Bly" = Bert Blyleven, Dutch-born American starting pitcher
- "Captain Hook" = George L. Anderson, American manager (also a second baseman, but this nickname is exclusive to his managing career)
- "Cat" = Frank Catalanotto, United States baseball player
- "Catfish" = Jim Hunter, American starting pitcher
- "CC" = Carston Charles Sabathia, American pitcher
- "Charlie Hustle" = Pete Rose, American multi-position player
- "Chick" = Arnold Gandil, American first baseman
- "Chicken" = Fred Stanley, American shortstop
- "The Chicken" = Ted Giannoulas, baseball mascot
- "Chicken Man" = Wade Boggs, American third baseman
- "Chico" = Cleotha Walker, United States baseball player
- "Chief" = Charles Bender, American starting pitcher
- "Chipper" = Larry Jones, Jr., American third baseman
- "Choo-Choo" = Clarence Coleman, United States baseball player
- "Chooch" = Carlos Ruiz, Panamanian catcher
- "El Chupacabra" (Spanish for "the goatsucker") = Yovani Gallardo, Mexican baseball player
- "The Closer" = Bruce Sutter American relief pitcher, known mostly for being brought in in the final innings of a game, long before the closing pitcher specality was made.
- "Cobra" = Dave Parker, American outfielder/DH
- "Cocky" = Eddie Collins, American second baseman
- "Coco" = Covelli Crisp, American center fielder
- "Colossus" = Mark McGwire, American first baseman
- "The Commerce Comet" = Mickey Mantle, American center fielder
- "Connie Mack" = Cornelius McGillicuddy, United States baseball player, manager, and team owner
- "Cookie" =
- Octavio Rojas, Cuban (later United States) outfielder and second baseman
- Carsten "CC" Sabathia, American starting pitcher, derisive nickname given to him by the Cleveland media due to his size and use of his initials
- "Cool Papa" = James Bell, United States baseball player
- "Country" = Enos Slaughter, American right fielder
- "Crime Dawg" = Fred McGriff, American first baseman/DH
- "Cy" = Denton Young, American starting pitcher
- "Cyclone" = Denton Young, American starting pitcher
Read more about this topic: List Of Baseball Player Nicknames