William Poromaa (born 23 December 2000) is a Swedish cross-country skier who competes internationally.
He competed at the FIS Nordic World Ski Championships 2021 in Oberstdorf, where he placed fourth in the relay with the Swedish team.
Poromaa is a son of former cross-country skiers Anette Fanqvist and . Poromaa is of Finnish descent through his paternal grandmother.
All results are sourced from the International Ski Federation (FIS).
<span style="font-size:95%">Distance reduced to 30 km due to weather conditions.</span>