"She's awesome," Dylan told US Weekly at an event in Hollywood this week. "They've been away for months working together in South Africa, so I haven't seen much of either of them.
Dylan Penn has opened up about her dad's romance with Charlize Theron
"She's great and they're amazing together. As long as my dad is happy, I'm happy for both of them."
Asked what makes Charlize so special, Dylan added, "Well, she's brilliant for one thing, and she's the only woman since my mum (actress Robin Wright) who can shut my dad up. The only woman!... She's a powerhouse."
Sean Penn and Charlize Theron
Charlize, 39, and Sean, 54, started dating earlier this year. They are currently in her native South Africa shooting drama The Last Face, which she is starring in, and he is directing.
Oscar-winner Charlize is a mum to adopted son Jackson, three, while Sean also has a son Hopper, 21, from his marriage to Robin.
Charlize Theron and Sean Penn started dating earlier this year
Sean was famously married to Madonna from 1985 until 1989. He went on to marry Robin in 1996, and the couple divorced in 2010. The House of Cards actress, 47, is now engaged to actor Ben Foster.