SPIDER-MAN THE ANIMATED SERIES (1990s)
"Sins of The Father, Chapter One: Doctor Strange"

THE INCREDIBLE HULK
"Mind Over Anti-Matter"

SPIDER-MAN AND HIS AMAZING FRIENDS
"7 Little Superheroes"

X-MEN (1996)
"The Phoenix Saga"
Very brief cameo appearance

OTHER CARTOONS:

Dr. Strange made 2 other brief appearances in Spider-Man and His Amazing Friends... One as a costume mannequin in Stan's Costume Shop in the episode "Triumph Of The Green Goblin" and the other as a dancing partygoer (with Clea?) in the episode "Spider-Man Unmasked!"

The Justice League episode "The Terror Beyond" featured a Defenders tribute, with Aquaman, Solomon Grundy and Dr. Fate taking over for Sub Mariner, Hulk and Dr. Strange.

Dormammu is rumored to have been the villain on an episode of the Spider Woman animated series from the 1980's.