Shannon was born and raised in south St. Louis, graduating from Christian Brothers College High School in 1957 as an all-state football, basketball and baseball player. He attended the University of Missouri before leaving in 1958 to begin his professional baseball career after signing with Bing Devine, GM of the St. Louis Cardinals. Shannon has commented that if football players were paid better during his era, he probably would have stayed at Missouri and sought a professional football career. He believed himself a better football player, and his former coach, Frank Broyles, commented that had he stayed in school, Shannon might have won the Heisman Trophy.
Shannon began his big-league career with the St. Louis Cardinals in 1962. In 1964, he became the team’s regular right fielder, shifting to third base (in order to make room for the newly acquired Roger Maris) in 1967. Shannon played in three World Series for the Cardinals. He hit a game-tying two-run homer off Whitey Ford in the Game 1 of the 1964 World Series against the New York Yankees, which St. Louis won 9-5. In Game 3 of the 1967 World Series against the Boston Red Sox, Shannon hit a key home run off Gary Bell. In Game 7 of the 1968 World Series against the Detroit Tigers, Shannon’s solo home run off Mickey Lolich was the Cardinals’ only run off Lolich as the Tigers clinched. Shannon also hit the last home run in the original Busch Stadium (Sportsman’s Park) in 1966 and the first one for the Cardinals in the second Busch Stadium (Busch Memorial Stadium). In 1970, he contracted nephritis, a kidney disease, which ended his playing career.
After his playing career, Shannon found he could excitement to the sports scene from the broadcast booth.
In 1972, he began his career as a member of the Cardinals broadcasting team, quickly earning the reputation as one of baseball’s best analysts. In 1985, Shannon was awarded an Emmy for his work on the Cardinals telecasts.
In addition to his broadcasting, Shannon in on the speaking circuit, is the sole proprietor of one of St. Louis’ finest restaurants and finds time to assist many charities.