Keough and Smith-Petersen met on the set of Mad Max: Fury Road in 2012. The actor confirmed the couple's engagement in a Facebook post in August.
Keough is the daughter of Lisa Marie Presley and Danny Keough and the eldest grandchild of Elvis and Priscilla Presley. The actress is best known for her roles in Magic Mike, Jack & Dianne and Mad Max: Fury Road.
Smith-Petersen is an Australian born stuntman.