Runner-up Hedgehog was unmasked to reveal comedian Jason Manford, while in third place was Katherine Jenkins who had performed as Octopus.
Roberts, who said she felt “sick” after being told she had won, started with a performance of Jocelyn Brown’s Somebody Else’s Guy before singing Lewis Capaldi’s Someone You Loved.
She said singing behind Queen Bee’s mask had given her extra confidence.
“I’ve loved it,” she said, adding: “It’s piping hot in there. . ”
Manford – as Hedgehog – opened with a rendition of Cry Me A River, made famous by Julie London in , before performing Little Mix’s Black Magic.
“I have loved this show. It’s been fabulous, ”he said.
“I have actually managed to keep it a secret from my children. They have just found out at the same time as you that Daddy is doing the show. ”
Asked about how his confidence had grown through the series, Manford added: “To walk out here to a crowd which is loving it, you come on with that confidence because the show gives you that confidence.”
Famous faces who have previously had their identities revealed on the show include former home secretary Alan Johnson, actress Denise Van Outen and former England footballer Teddy Sheringham.
The final began with all the performers donning their costumes for a group rendition of the greatest show from the greatest showman.
Comedian Jason Manford was runner up (John Phillips / Getty)
Octopus was the first to be unmasked to reveal Welsh classical singer Katherine Jenkins who had performed Supercalifragilisticexpialidocious from Mary Poppins before she left the show following an audience vote.
She said she had initially kept her “opera voice” under wraps on the show to protect her identity, and had enjoyed performing as Octopus as her normal career could be “quite serious”.
Jenkins said she had enjoyed creating “a new character”, and had imagined performing for her four-year-old daughter Aaliyah when she dressed as Octopus.
The show, which is based on a South Korean format, has been watched by millions since coming to the UK.
Other celebrities who have been unmasked on the show include Jake Shears from Scissor Sisters, singer Kelis and East Enders star Patsy Palmer.
The Darkness frontman Justin Hawkins, singer CeeLo Green and Skunk Anansie’s Skin have also had their identities unveiled.