Mariano Rivera (born November 29, 1969) is a dominant relief pitcher for the New York Yankees. Born in Panama City, Panama, his rookie season in the Major Leagues was 1995, in which he made a limited number of appearances. In 1996, he served primarily as a set-up man for the closer John Wetteland. During that season, if the Yankees were leading after 6 innings, they were nearly assured of victory due to the stellar pitching of both relievers.

When Wetteland left the team following that season (in which they won the World Series), Rivera became the Yankees' closer and has remained so ever since. He has been perhaps the most consistent, dependable relief pitcher in the Major Leagues as a closer for the Yankees. Rivera has been especially overpowering in the postseason, in which his lifetime earned run average, under 1 run per nine innings pitched, is among the best ever. His contribution to the general success of the Yankees since 1996, including 4 World Series championships, has been very significant.

Rivera has won the Rolaids Relief Man of the Year Award twice, in 1999 and 2001. He donated his 2001 trophy to the New York City Fire Department. It is on permanent display at the FDNY's Brooklyn headquarters.

His demeanor on the mound is very serious. His best pitches are the fastball and changeup. On a per-batter basis, he probably breaks more bats than any other current pitcher, caused by jamming them with the fastball.

As Rivera enters a game in Yankee Stadium, the song "Enter Sandman" by Metallica is played on the loudspeaker system.

His uniform number is 42, which has been retired by all Major League Baseball teams since 1997 in honor of Jackie Robinson. However, Rivera is able to have the number due to a grandfather clause.