Luke Hemsworth returned to Australia because he was worried about school shootings in Los Angeles.
The 'Westworld' actor - who has Holly, 11, Ella, 10, Harper, eight, and seven-year-old Alexandre with wife Samantha - recently relocated back to his native country and he admitted the decision was motivated by the potential dangers his brood could face as they got older.
Asked by Nova 96.9's Fitzy & Wippa if they had had enough of California after seven years there, Luke explained the relocation was "more about the kids".
He added: "We didn't want the kids to go to high school over there, with machine guns and things. So yeah, it was time to come back!"
And the 36-year-old star is confident they made the right decision.
He said: "The difference in seeing them, how happy they are back here, that was really interesting."
Luke revealed the family are living close to his famous brother Chris Hemsworth and his clan when the hosts commented on his "Byron Bay tan".
He laughed: "Back in Byron baby, back to the motherland."
Meanwhile, the actor - who plays head of Westworld security Ashley Stubbs in the dystopian drama series - teased what's ahead in the upcoming third season of the show.
He said: "We get to see exactly what that real world is, and while it's shiny and beautiful on the outside, inside it's kind of rotten."
Luke's youngest brother, Liam Hemsworth, has previously claimed the famous siblings are all very "competitive".
He said: "I was the youngest, so I was never really anywhere near their physicality. If they wanted to beat me up, they would. But I idolised them. As a kid, I followed them into anything and wanted to do whatever they were doing. And it was always competitive."