Even then though, she was refreshingly responsible with her finances.
Gellar, 41, has been acting since she was a kid — from a series of Burger King commercials in the early 1980s to a role on "All My Children" in the mid '90s. But she may be most well-known and loved for starring in the WB's hit show "Buffy the Vampire Slayer," which debuted in 1996.
So what did a teenage Gellar do with her first "Buffy" paycheck?
"I saved it, " Gellar tells CNBC Make It.
"I think I was very well aware already...you heard all those stories about actors that make money and people run off with it. And I remember thinking, 'If I ever had money like that, I would know where it was at all times.'"
Still, Gellar did treat herself one thing: a new car. But even that she did responsibly.
"I remember I was the last one to get a new car," Gellar says, referring to her "Buffy" co-stars. "I got a new car the second season of the show. I was the last one; everyone else had gotten it.