In 1998, he returned to Hawaii where he was discovered by international designer Takeo and launched his modelling career. In 1999 he won Hawaii's Model of the Year and hosted the Miss Teen Hawaii contest. Momoa is best known for his roles as Jason Ioane (1999-2001) in Baywatch and as Ronon Dex (2005- ), an elite firearms and mêlée warrior in Stargate Atlantis.

On July 23, 2007 Lisa Bonet gave birth to their first child, a girl, named Lola Iolani Momoa.

After Stargate Atlantis season 4 shooting was over, Jason Momoa had his dreadlocks cut off. The weight of them was causing him headaches, and even whiplash when filming action scenes. It may be that they sew them back on for the start of Season 5 filming in july 2008.