The trio were confirmed as participants in the Bravo reality show at an event in Manhattan last night, Us Weekly reports.
They are intended as replacements for former stars Cindy Barshop, Alex McCord, Jill Zarin and Kelly Bensimon, who were dropped from the show last year.
Drescher, a mother of three, is married to a noted banker and is a cousin of comedic actress Fran Drescher. Her left foot and ankle were amputated when she was 6 years old after an accident.
Radziwill is the widow of Prince Anthony Radziwill, the nephew of Jackie Kennedy Onassis. She has previously worked for ABC News and Glamour.
Meanwhile, Thomson, who has two children, designs the line Yummie Tummie and previously worked as a celebrity stylist.
Stars LuAnn de Lesseps, Ramona Singer and Sonja Morgan will all return for the new season of Real Housewives of New York, which will air on Bravo.
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