Florian Janistyn (born 22 April 1988) is an Austrian swimmer, who specializes in long-distance freestyle events.

[1][2] He is a two-time Austrian national record holder in both 800 and 1500 m freestyle, and also, a current member of SG Wiener Neustadt, under his personal coach Erich Neulinger.

He swam on the second leg of the men's 4 × 200 m freestyle relay, posting a split time of 1:50.48.

Janistyn and his teammates Dominik Koll, Markus Rogan, and David Brandl finished heat two in fifth place and ninth overall, with a total time of 7:11.45.

[4] Three days later, Janistyn won the first heat of his only individual event, the 1500 m freestyle, by sixteen seconds ahead of Bulgarian swimmer and three-time Olympian Petar Stoychev, with a new Austrian record time of 15:12.46.