The duo will sit alongside regulars including Carol Vorderman, Lisa Maxwell and Carol McGiffin, while Coronation Street's Shobna Gulati and Debbie Rush will also spend a day on the panel.
Heather Trott actress Fergison, who appears today (Tuesday, April 10), said: "I'm a huge fan of Loose Women and being on the panel with these fantastic ladies is a dream come true."
Gulati, Sunita Alahan in ITV1's Manchester serial, commented: "I have always enjoyed being a guest on the show so am really looking forward to being one of the Loose Women and voicing my opinions. Everyone's viewpoint is discussed and everyone gets to have their say."
Cassidy, who competed alongside Denise Welch in the most recent series of Celebrity Big Brother, said that she is hoping to "impress" during her appearance on Friday.
"Ever since Celebrity Big Brother people have been tweeting that they'd love to see me as a Loose Woman and now it's happening," Cassidy told The Mirror. "I can be very opinionated."
Thanking fans for their support on Twitter, the 28-year-old added: "So excited about Friday, my chance to get loud and loose!"
Loose Women's executive producer Sharon Powers added: "We're very much looking forward to throwing ourselves into the world of soap at Loose Women. Cheryl, Shobna, Debbie and Natalie will each bring something unique to the panel but they're all guaranteed to add a sense of fun throughout Easter."
Loose Women continues weekdays at 12.30pm on ITV1.
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