Reginald Martinez Jackson is an American former professional baseball right fielder who played 21 seasons in Major League Baseball (MLB) for the Kansas City / Oakland Athletics, Baltimore Orioles, New York Yankees, and California Angels. Jackson was inducted into the National Baseball Hall of Fame in 1993 in his first year of eligibility.
Jackson was nicknamed "Mr. October" for his clutch hitting in the postseason with the Athletics and the Yankees. He helped Oakland win five consecutive American League West divisional titles, three straight American League pennants and three consecutive World Series titles from 1972 to 1974. Jackson helped New York win four American League East divisional pennants, three American League pennants and back-to-back World Series titles, in 1977 and 1978. He also helped the California Angels win two AL West divisional titles in 1982 and 1986. Jackson hit three consecutive home runs at Yankee Stadium in the clinching game six of the 1977 World Series.
Jackson hit 563 career home runs and was an American League (AL) All-Star for 14 seasons.