Yen Sid spoke for the first time in an episode of the "Wonderful World of Disney" (1971) called "Disney On Parade", in which he was voiced by Michael Rye. At the time his name was unknown, and he was referred to as "Merlin" by mistake. But his name was corrected when Kingdom Hearts II came out, almost 35 years later. He is voiced by Corey Burton, who still does Yen Sid's voice in other Disney animations.

Yen Sid's name is simply "Disney" backwards, and is supposed to represent Walt Disney himself.