Onan Orlando Thom (born April 11, 1984) is a Guyanese former swimmer, who specialized in sprint freestyle events.

[1] Thom qualified for the men's 100 m freestyle at the 2004 Summer Olympics in Athens, by receiving a Universality place from FINA, in an entry time of 54.14.

[2] He challenged seven other swimmers in heat two, including three-time Olympian Aleksandr Agafonov of Uzbekistan.

Thom failed to advance into the semifinals, as he placed fifty-ninth overall out of 71 swimmers in the preliminaries.

This biographical article related to a Guyanese swimmer is a stub.