Zoe, 29, starred alongside Gareth Gates, Will Young and Darius Campbell (formerly Danesh) in the 2001 series of the reality show and came fourth.
Last night, however, Zoe hung up her microphone and headed into the BB compound alongside two fellow new housemates - Biannca Lake and Pav Paul.
In her introduction, Zoe told viewers that they might recognise her from starring in the first series of Pop Idol.
Speaking in a video on the Big Brother website, Zoe also said: "I'm going to go in there and bring a new fresh buzz to the house and get rid of that nasty vibe that's going on in there.
"To get the viewers on my side, I'd like to think I'd just be myself. I'm quite cheeky, mischievous, bubbly, honest and I'm genuine. If that's what people like, then hopefully they'll vote for me."
Since starring in Pop Idol, Zoe focused on a stage career and has appeared in the West End shows Thriller-Live and Priscilla Queen Of The Desert.
Unbeknown to the original housemates, the three newbies will be voting someone out on Friday night. Meanwhile, unbeknown to them, one of the newbies will also be shown the door!
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