Theodor “Theo” Kleine won a silver medal at the 1956 Olympic Games at Melbourne in flatwater canoeing in the K2-10,000 metres with Fritz Briel. Kleine also competed at the flatwater World Championships and won a bronze medal in 1954 in the K2-10K event with Ernst Steinhauer, and in 1958 in the K4-1000 (together with Michel Scheuer, Gustav Schmidt, and the non-Olympian Georg Lietz), and in the K4-10K the same year with the same crew. At the European Championships he won a gold medal in the K4-10K in 1957 and 1959, and silver medals in the K4-1000 on both occasions. Domestically Kleine earned 23 national titles (K2-500: 1955-56; K2-1000: 1948, 1950; K2-10K: 1947-51 and 1958; K4-1000: 1955-59; K4-10K: 1955, 1959; 4×500 relay: 1955-59; and Team-K1: 1956). In 1960 he retired from competition and then worked as a sports teacher.