The Jetsons Meet the Flintstones (1987)

Elroy Jetson invents a time machine that takes him back to prehistoric times, where he meets the Flintstone family.

Unfortunately the movie The Jetsons Meet the Flintstones is not yet available on HBO Max.

Mel Blanc

as Barney Rubble / Dino / Mr. Spacely (voice)
Daws Butler

as Elroy Jetson / W.C. Cogswell / Henry Orbit (voice)
Don Messick

as Astro / R.U.D.I / Mac / Announcer / Store Manager / Robot (voice)
Henry Corden

as Fred Flintstone / Knight (voice)
Jon Bauman

as Iggy (voice)
Hamilton Camp

as Turk Tarpit (voice)
Julie McWhirter

as Betty Rubble / Jet Rivers / Investor / Panelist / Harem Girl (as Julie Dees) (voice)
George O'Hanlon

as George Jetson (voice)
Penny Singleton

as Jane Jetson (voice)
John Stephenson

as Mr. Slate / Moderator / Investor / Poker Player (voice)
Brenda Vaccaro

as Didi (voice)
Jean Vander Pyl

as Wilma Flintstone / Rosie / Mrs. Spacely (voice)
Janet Waldo

as Judy Jetson / Female Computer (voice)
Frank Welker

as Dan Rathmoon / Johnny / Mr. Goldbrick (voice)
Patric Zimmerman

as (voice)