The actor, who plays Emmett Cullen in the vampire movies, reportedly met Vinson through a mutual friend and they have now been photographed strolling through Venice Beach together.
A friend of the duo told Us Weekly that they've been dating for about "two months", adding: "She's a lot of fun. They are both very into working out. They hang out in Venice a lot and just stay low-key."
> Kellan Lutz: 'I'm looking for a normal girl'
> Sharni Vinson 'grateful to mum for career'
Lutz previously dated 90210 AnnaLynne McCord for about two years, but he confirmed that he is "definitely single" in May this year. He later revealed that what attracts him most to a woman is a pretty, natural face".
He said: "A girl's face gets my attention. The face has so much, and I love the eyes and a big smile. Especially if you can wake up next to them in bed and they still look the same after a long night of watching movies with strawberries and champagne and cuddling. That's sexy!"
Vinson, who has had roles in Step Up 3D and Blue Crush 2, initially moved to Los Angeles from Australia to be with long-distance boyfriend, CSI: NY actor AJ Buckley. They later split.
Watch the teaser trailer for Twilight: Breaking Dawn - Part 1 below: