Hjalti Guðmundsson (born March 20, 1978) is an Icelandic former swimmer, who specialized in breaststroke events.

[1] During his sporting career, Gudmundsson swam for the club Sundfélag Hafnarfjarðar, and later represented Iceland at the 2000 Summer Olympics.

Gudmunsson competed in the men's 100 m breaststroke at the 2000 Summer Olympics in Sydney.

[2] He achieved a FINA B-cut of 1:04.57 from the Mare Nostrum meet in Barcelona, Spain.

[3] He challenged seven other swimmers in heat four, including two-time Olympians Valērijs Kalmikovs of Latvia and Arsenio López of Puerto Rico.