Caroline Gilchrist Rhea (born April 13, 1964) is a Canadian stand-up comedienne, actress, and model who is perhaps best known for playing Aunt Hilda Spellman on the ABC/WB Network fantasy sitcom, Sabrina, the Teenage Witch from 1996 to 2003, and for being the original host of the NBC reality television show The Biggest Loser since 2004 until she was replaced by Alison Sweeney after the end of the third season in 2006.

Her Disney roles include Linda Flynn and Grandma Betty Jo in Phineas and Ferb, Ilsa Shickelgubermeiger-Von Helsing der Keppelugerhofer in The Suite Life of Zack and Cody, Lynette Hansen in Mom's Got a Date with a Vampire, and Mrs. Konquist in the Fillmore! episode "Nappers Never Sleep."