Why was Lacey Chabert replaced as Meg on Family Guy?

Answer 1

Seth MacFarlane is quoted as saying...

"You know, it was just purely a contractual thing with Lacey. There was a mistake in her contract, and I guess she had not intended to be involved for, like, the full run of the show. I don't even remember. To be honest, I don't really, to this day, know what it was. It was nothing there was no tension or anything. She wanted to go, and she was very cool about it. We obviously don't want to keep anyone there who doesn't want to be there. So, you know, it was early on enough in the show that it wasn't a huge that happens from time to time, you've got to replace a voice actor. Fortunately, what Mila brought to it was in a lot of ways, I thought, almost more right for the character. I say that Lacey a phenomenal job, but there was something about Mila, something very natural about Mila".

Answer 2

Very simple... Lacey Chabert was only contracted for the first season. She left and Mila was cast.