Mariano Rivera (born November 29, 1969, in Panama City, Panama) is a professional baseball player. He is a relief pitcher for Major League Baseball's New York Yankees. He throws and bats right-handed. Nicknamed "Mo," Rivera originally began his Major League career as a starting pitcher in , but it was after he was moved to the bullpen and converted to closer that he found success. He has subsequently become one of the premier closers in the majors.

Some people within the baseball world often refer to Rivera as the greatest postseason relief pitcher and the greatest closer in baseball history. Along with having the third-most career regular season saves in Major League history, Rivera is the Major League's all-time postseason leader in saves and ERA. In his career with the Yankees, Rivera has won 4 World Series titles.

Rivera is well-known for his signature pitch, a sharp-breaking cut fastball. He is the last active MLB player to wear the uniform number 42, which was retired throughout baseball in in honor of Jackie Robinson.