She will join 15 other stars living in close quarters in a house bedecked to look like a vaudeville-style theatre.
Westbrook has previously spoken to Premier about her Christian faith describing how her life changed following a visit to a church.
The 42-year-old has the Bible verse Isaiah 54:17 tattooed on her wrist.
She told Premier: "I always feel - especially coming from a working class background and being in the public eye - people judge, judge, judge and they use judgement as a weapon against people, to make them feel terrible about themselves.
"So, for me [the verse says] 'God's there for you and no weapon formed against you shall prosper'. So that's the Bible verse for me."
The former drug addict told Premier about the time she became a Christian: "I always felt that there was something bigger out there than me. At Cocaine Anonymous they always refer to a 'higher power', and for me that higher power was God.
"I just didn't realise that you can have a relationship with Jesus in the way that I understand that you can today. When I was in treatment in Arizona (when I finally got clean) I was pregnant with my daughter and I couldn't sleep.
"They had a 'serenity path' in the garden. I went and sat out there at about 3am. There's this thing called the Phoenix Lights, when the sky lights up in different colours.
"I sat there, looking at the sky, and I just had a conversation with God. This was way before I was a Christian, but I said to him, 'This is really hard and I can't do this on my own. But if I'm meant for more than to just be working in television and wasting my life doing other stuff, then you need to step in and help me out because I can't do it on my own.'
"I felt that was my first real connection with God."
The Only Way Is Essex star Gemma Collins and Strictly Come Dancing professional Kristina Rihanoff are also taking part.
The show's producers have promised "unwelcome surprises" for the stars, while revealing "the BB garden has been transformed into a Whitechapel style foggy street scene with a Victorian pub snug".
Former Apprentice candidate James Hill won Celebrity Big Brother last year.
