William Michael Conigliaro (born August 15, 1947 in Revere, Massachusetts) is a former Major League Baseball outfielder who played in the American League for the Boston Red Sox (1969-1971), Milwaukee Brewers (1972) and Oakland Athletics (1973). He is the younger brother of Tony Conigliaro; Billy and Tony were Red Sox teammates in 1969 and 1970.
Conigliaro showed great promise as a hitter in his years in Boston, totaling 42 doubles and 29 home runs as a Red Sox outfielder in 1970 and 1971. He finished 8th in the American League in doubles in 1971, his most productive year in the majors. In 1970, he was 10th in American League in being hit by pitches with 7. His most memorable game may have been on July 4, 1970, when both Billy and Tony homered against the Cleveland Indians.
After the 1971 season, Billy was traded from the Red Sox to the Brewers in a blockbuster deal that also included Ken Brett, Jim Lonborg, George Scott, Tommy Harper and Marty Pattin. Billy, who idolized his older brother Tony, had been highly critical of the Red Sox for trading his brother to the Angels, especially after Tony's remarkable 36 home runs during the 1970 season after his famous "beaning" incident in 1967. Unhappy in Milwaukee, he announced his retirement from baseball in the middle of the 1972 season. He came back to baseball in 1973 as a part-time player with the eventual World Champion Athletics, making brief appearances in the American League Championship Series and the World Series. Once again Billy became disgruntled with ownership, (this time in Oakland), and retired at the conclusion of that season. He attempted a comeback with the A's several years later, but ultimately retired for good after being assigned to their triple A affiliate on what was to be a "temporary" basis.