Balázs Gercsák (born 14 October 1986) is a Hungarian swimmer, who specialized in freestyle events.

He is also the brother of open water swimmer Csaba Gercsák, who won the bronze medal in the 25 km marathon at the 2011 FINA World Championships in Shanghai, China.

Swimming the second leg in heat two, Gercsak recorded a split of 1:54.03, but the Hungarians rounded out the field to last place and sixteenth overall with a final time of 7:31.78.

Leading up to his second Games, he posted a lifetime best and FINA B-standard entry time of 3:52.21 at the Hungarian National Trials in Budapest.

[4] He challenged six other swimmers on the second heat, including Greece's Spyridon Gianniotis, Switzerland's Dominik Meichtry, and South Africa's Jean Basson.