Petticoat Junction to The Bold and the Beautiful

Petticoat Junction was a spin-off of The Beverly Hillbillies.

The Beverly Hillibillies? Granny appeared on an episode of Mister Ed (see below for more on The Beverly

Hi Honey, I'm Home!'s Lloyd was friends with Mister Ed

Alice & Trixie from The Honeymooners crossed over onto Hi Honey, I'm Home!

Here's Lucy's Lucy was driven around Miami by Ralph Cramden of The Hooneymooner's

Here's Lucy's Lucy Carter and Mannix's Mannix are held hostage in an episode of Here's Lucy.

Mannix returned to TV on an episode of Diagnosis Murder to solve an old unsolved case with the help of Dr Mark Sloan.

Diagnosis Murder's Dr Mark Sloan was defended by Matlock when Sloan was accused of murder

Both have characters that have flown on the fictional Trans Global Airlines

The Young and the Restless and The Bold and the Beautiful crossed over multiple times.