The two became romantically linked earlier this year.
"Jason and Eiza are hanging out again when it's convenient and when they're in the same place," the source says. "They're both busy in their own lives and with work, so it's difficult to have a serious relationship, but they do still enjoy each other's company and like each other."
The 42-year-old Aquaman star was romantically linked to the 30-year-old actress earlier this year following Momoa's split from wife Lisa Bonet. ET's source said at the time that the couple had started out as friends but always had an "underlying chemistry."
The fling ended quickly, though, and a source said last month that Momoa and Gonzalez were going their separate ways. It's unclear where their relationship will go following their reconnection this week.
Momoa and Bonet were together for 20 years before separating in January. A source told ET at the time that the two "are still committed to being friends for the sake of their family."
The source added, "They both want each other to be happy."