The network made the announcement during its telecast of "The Bachelor Pad."
Palin -- a daughter of former Republican vice presidential nominee and former Alaska Gov. Sarah Palin -- joins Hasselhoff, the star of "Baywatch," for the show's 11th season when it premieres with a 2-hour episode Sept. 20, ABC said.
Also in the cast are model-actress Audrina Patridge, singer-actress Brandy, actresses Florence Henderson and Jennifer Grey, and former NFL star Kurt Warner. The cast also includes actor Kyle Massey, comedian Margaret Cho, singer Michael Bolton, "The Jersey Shore" star Mike "The Situation" Sorrentino and former NBA star Rick Fox.