Waldo's daughter Lucy Lee confirmed to ABC News that Waldo died Sunday morning.
Watch an excerpt from an old Jetsons episode here:
Lee said her mother had been diagnosed with a benign, but inoperable brain tumor five years ago.
Waldo, a Washington native, played several roles for radio and television, but was best known for her work as Judy Jetson, the teenage daughter of George and Jane Jetson.
"The Jetsons" ran from 1962 to 1987 and included a big-screen adaption in 1990 called "Jetsons: The Movie."
IN MEMORIAM: Celebrities and notable figures who have recently passed away