Sean Penn wanted to name his son Steak.
The Milk actor tried to persuade his then-wife Robin Wright - with whom he has kids Dylan, 25, and Hopper, 22 - to give their youngest child a meaty moniker in honour of his love of beef, but the House of Cards star refused.
Hopper revealed: "My dad wanted to name me Steak, the food, because he loves it so much.
"But my mom was never going to go for it. What they told me is that I hopped in her stomach, I didn't kick, so they went with that."
Hopper is also named in honour of his father's "idol", actor Dennis Hopper.
He said: "[My name] has to do with Dennis Hopper; my dad was friendly with him and idolized him."
Despite his famous parents, Hopper never had an interest in being an actor until his father forced him to appear in his latest directorial effort The Last Face, which also stars Javier Badem and Sean's former girlfriend Charlize Theron.
Hopper recalled to Interview magazine: "Two and a half years ago, my dad was working on his movie called The Last Face, and I asked if I could PA for it.
"He said, 'No, you're going to act in it.' I said no, because I'm very shy; I didn't know how to act.
"He said, 'Well, you'll get paid.' So I was like, 'I'm on board.' After the first day, I fell in love with it."
The War Machine star insists he is never going to be as good an actor as his father.
He said: "My dad is a really good actor, and there are a lot of s***ty actors, and I definitely think I'm one of them."