Denis Pankratov (Russian: Денис Панкратов; born 4 July 1974) is a retired Russian butterfly swimmer of the 1990s, who was best known for winning the butterfly double at the 1996 Summer Olympics in Atlanta, United States in a unique style.

In his first international appearance at senior level, he placed 6th in the final of the 200 m butterfly at the 1992 Summer Olympics in Barcelona.

He held the 100 m butterfly world record for over two years, until it was broken by Michael Klim.

[1] His submarine technique caused a rule change to restrict butterfly swimmers to 15 m underwater (humans swim slower than the speed which they gain from diving and gliding and bouncing off the walls), in line with the other strokes.

Pankratov attempted to repeat his success at the 2000 Summer Olympics in Sydney and finished 7th in the 200 m butterfly.