The heiress, whose 1974 kidnapping still draws national interest, appeared on The CW drama as a fictional Hearst relative who visits the series' title character at college, TVGuide.com reported.
The 52-year-old Hearst, who has been in several films by director John Waters, said she was hesitant to appear on the series as a character so clearly linked to her real persona.
"I wanted to know exactly what it was about, because I'd never gone in and done a cameo as myself in anything, and I wouldn't do that," she said of the role.
Hearst also said that while the nation's ongoing interest in her kidnapping still bothers her, she has managed to make some degree of peace with her situation.
"It doesn't really concern me that people don't move on," she told TVGuide.com.
"I'm also guessing that the audience of 'Veronica Mars' doesn't remember all that," she added. "I won't be a distraction for them. They can focus in on the juicy story line."