The Ex-wife of Smithers is the ex-wife of Waylon Smithers. She had a very brief appearance in the episode "Secrets of a Successful Marriage", where she appears in a flashback where it is said that Smithers was briefly married to her, but they divorced because he devoted a lot of time to Mr. Burns, whom she disliked because of his generally cold-hearted and often selfish personality, notably towards her husband.

It is possible that Smithers would leave her to be with Mr. Burns, or that she was the one who abandoned him because he dedicated a lot of time to Mr. Burns.