| Birth Date: | 9 December 1917 |
| Birth Place: | Budapest, Austria-Hungary |
| Death Place: | Budapest, Hungary |
| Sport: | Water polo |
Dezső Lemhényi (né Kollmann, December 9, 1917 – December 4, 2003) was a Hungarian water polo player who competed at the 1948 Summer Olympics and 1952 Summer Olympics. He was the husband of Olga Tass.
Lemhényi was part of the Hungarian team which won the silver medal at the 1948 tournament. He played six matches and scored three goals.
Four years later he was a member of the Hungarian team which won the gold medal at the 1952 Olympic tournament. He played two matches and scored five goals.
He is one of a few sportspeople who won Olympic medals in water polo as players and head coaches.[1] He was inducted into the International Swimming Hall of Fame.[1]