The actress and model sported a diamond engagement ring in a photo posted by her new fiancé, Australian stuntman Ben Smith-Petersen.
"So that happened," he captioned the pic with Keough, 25.
The daughter of singer Lisa Marie Presley, Keough was previously engaged to Alex Pettyfer, her Magic Mike costar, and dated singer Ryan Cabrera.
Ben Smith-Petersen / Facebook
Keough's rep has not responded to calls asking for comment.