Cohen, 33, and Fisher, 28, who played Shannon in the Australia TV soap "Home and Away," will have a traditional Jewish wedding, London's Sun reported Friday.
"I will definitely have a Jewish wedding just to be with Sasha," Fisher said. "I would do anything -- move into any religion -- to be united in marriage with him."
Fisher studied Hebrew in order to please Cohen's devout parents, the Sun said.
Cohen's first series on HBO, "Ali G In Da USA," was a big hit and the comedian is working on a new project in Los Angeles.
Fisher said a specific wedding date has not been set, but the couple will live in Cohen's home in Hampstead, North London.