At the 2008 Summer Olympics, Deibler finished in 38th, 33rd and 15th place in the 50 m, 100 m, and 4 × 100 m freestyle events. He improved at the 2012 Olympics, finishing fourth in the 100 m butterfly and sixth in the 4 × 100 m medley relay. At the 2016 Summer Olympics in Rio de Janeiro, he competed in the 100 m butterfly where he finished 18th in the heats and did not qualify for the semifinals. He also competed as a member of the 4 x 100 m medley relay team that finished in 7th place.