Campanella played for the Brooklyn Dodgers during the 1940s and 1950s, as one of the pioneers in breaking the color barrier in Major League Baseball. His career was cut short in 1958 when he was paralyzed in an automobile accident. May 7, 1959, the Dodgers, then playing their second season in Los Angeles, honored Campanella with Roy Campanella Night at the Los Angeles Memorial Coliseum. The New York Yankees agreed to make a special trip to Los Angeles to play an exhibition game against the Dodgers for the occasion. The Yankees won the game, 6–2. The attendance at the game was 93,103, setting a record at that time for the largest crowd to attend a Major League Baseball game. The proceeds from the game went to defray Campanella's medical bills. In 1969, Campanella was inducted into the Baseball Hall of Fame, the second player of African American heritage so honored, after Jackie Robinson. The same year, he received the Bronze Medallion from the City of New York.
On June 4, 1972, the Dodgers retired Campanella's uniform number 39 alongside Robinson's (42) and Sandy Koufax's (32). In an article in Esquire magazine in 1976, sportswriter Harry Stein published an article called the "All Time All-Star Argument Starter," a list of five ethnic baseball teams. Campanella was the catcher on Stein's black team.
In 1999, Campanella ranked number 50 on The Sporting News' list of the 100 Greatest Baseball Players, and was a nominee for the Major League Baseball All-Century Team.
In 2006, Campanella was featured on a United States postage stamp. The stamp is one of a block of four honoring baseball sluggers, the others being Mickey Mantle, Hank Greenberg, and Mel Ott.