Theodore Roosevelt "Double Duty" Radcliffe (July 7, 1902 – August 11, 2005) was an American professional baseball player in the Negro leagues. An accomplished two-way player, he played as a pitcher and a catcher, became a manager, and in his old age became a popular ambassador for the game. He is one of only a handful of professional baseball players who lived past their 100th birthdays, next to Red Hoff (who lived to 107) and fellow Negro leaguer Silas Simmons (who lived to age 111).

Newspaperman Damon Runyon coined the nickname "Double Duty" because Radcliffe played as a catcher and as a pitcher in the successive games of a 1932 doubleheader between the Pittsburgh Crawfords and the New York Black Yankees. In the first of the two games at Yankee Stadium, Radcliffe caught the pitcher Satchel Paige for a shutout and then pitched a shutout in the second game. Runyon wrote that Radcliffe "was worth the price of two admissions." Radcliffe considered his year with the 1932 Pittsburgh Crawfords to be one of the highlights of his career.

Of the six East–West All-Star Games in which he played, Radcliffe pitched in three and was a catcher in three. He also pitched in two and caught in six other All-Star games. He hit .376 (11-for-29) in nine exhibition games against major leaguers.

Ted Radcliffe grew up in Mobile, Alabama as one of ten children. His brother Alex Radcliffe also achieved renown as a ballplayer playing third base. The boys played baseball using a taped ball of rags with their friends including future Negro league All-Star ballplayers Leroy "Satchel" Paige and Bobby Robinson.

In 1919, teenagers Ted and Alex hitchhiked north to Chicago to join an older brother. The rest of the family soon followed to live on the South Side of Chicago. A year later Ted Radcliffe signed on with the semi-pro Illinois Giants at $50 for every 15 games and 50¢ a day for meal money. This worked out at about $100 a month. He travelled with the Giants for a few seasons before joining Gilkerson's Union Giants, another semi-pro team with whom he played until he entered the Negro National League with the Detroit Stars in 1928.

After a brief tenure with the Detroit Stars, Radcliffe played for the St. Louis Stars (1930), Homestead Grays (1931), Pittsburgh Crawfords (1932), Columbus Blue Birds (1933), New York Black Yankees, Brooklyn Eagles, Cincinnati Tigers, Memphis Red Sox, Birmingham Black Barons, Chicago American Giants, Louisville Buckeyes and Kansas City Monarchs. Ted Radcliffe managed the Cincinnati Tigers in 1937, Memphis Red Sox in 1938 and Chicago American Giants in 1943.

Radcliffe was known as a glib, fast-talking player. Ty Cobb reported that Radcliffe wore a chest protector that said "thou shalt not steal" during one exhibition game. He could call a clever game as a catcher and his banter from the pitching mound distracted some hitters. Biographer Kyle P. McNary estimates that Radcliffe had a .303 batting average, 4,000 hits and 400 homers in 36 years in the game (see Baseball statistics).

Standing 5 ft 9 in and weighing 210 pounds (95 kg) Radcliffe had a strong throwing arm, good catching reflexes and great cunning. Even with these strengths, he also mastered many illegal pitches including the emery ball, the cut ball and the spitter. Statistics for the Negro league baseball are incomplete, but available records show him hitting .273 over eight of his 23 seasons.