Robert "Bob" Lucien LeGendre (January 7, 1898 – January 21, 1931) was an American track and field athlete. He competed in the pentathlon at the 1920 and 1924 Summer Olympics and finished in fourth and third place, respectively. He failed to qualify for the 1924 Olympics in the long jump, yet at the 1924 Olympic pentathlon competition he set a world record in that event at 7.76 metres (25.5 ft). He won the pentathlon at the Inter-Allied Games in 1919, beating Eugene Vidal and Géo André.
While studying at the Georgetown University, LeGendre also played American football and baseball. He earned Ph.D. and D.D.S. degrees there and signed a Hollywood contract as a film actor. He abandoned the movie career and became a dentist in Washington.