The publication's annual awards ceremony - which celebrates the year's most inspirational figures and their achievements - was hosted by mum-to-be Fearne Cotton and held at the V&A Museum in London.
Tulisa - who wore a canary yellow dress to the bash - took home the coveted Ultimate TV Personality gong for her role on The X Factor panel.
Accepting her award, the N-Dubz stunner stated: "For the first time in as many nights I'm actually sober! Giving myself an applause for that.
"Wow. How amazing to be voted best TV personality. I love working on The X Factor, and now, in year two, I hope I've earned my place on the panel."
She went on to dedicate the gong to PA Gareth Varey - who broke his leg the previous evening following The Daily Mirror's Pride of Britain Awards.
Tulisa's colleague Nicole Scherzinger won the Ultimate Fun Fearless Female prize, with her X Factor finalists presenting her with the trophy.
The former Pussycat Dolls star - who showed off her curves in a stunning backless dress - was quoted by The Daily Mail as saying: "It made it so much better to have my little pumpkins up there giving it to me. They’re just so sweet, it makes me so happy, God bless ‘em."
Despite not being present at the ceremony, Cheryl Cole was named the Ultimate Popstar, while One Direction won the Ultimate Men accolade - with a video message from absent Harry Styles claiming: "We cannot believe we’ve been voted Ultimate Men of the Year because most people still say that we’re boys."
Kim Kardashian and her sisters Kourtney and Khloe picked up the accolade for Ultimate Confidence Queens and Kelly Osbourne was on hand to collect her prize for being this year's Ultimate Style Icon, stating appearing on the mag's cover "did wonders" for her self-esteem.
Olympic gymnast Louis Smith was crowned Ultimate Hottie, with fellow Team GB star Jessica Ennis taking home the Ultimate Olympian gong. Sarah Storey received the Ultimate Paralympian trophy.
The Hunger Games star Jennifer Lawrence was awarded Ultimate Film Actress, while Vicky McClure - star of This Is England - was named Ultimate UK TV Actress.
The Editor's Choice award was presented to Stephanie Kercher, whose sister Meredith Kercher was murdered five years ago in Perugia, Italy.
Cosmopolitan's Ultimate Women Awards 2012 - Full Winners List:
Ultimate Fun Fearless Female – Nicole Scherzinger
Ultimate Style Icon with VO5 – Kelly Osbourne
Ultimate Confidence Queens – Kourtney, Kim and Khloe Kardashian
Ultimate TV Personality – Tulisa Contostavlos
Ultimate Olympian – Jessica Ennis
Ultimate Paralympian – Sarah Storey
Ultimate Hottie – Louis Smith
Ultimate Pop Star – Cheryl Cole
Ultimate Men – One Direction
Ultimate UK TV Actress – Vicky McClure
Ultimate International TV Actress – Melissa George
Ultimate Newcomer – Zawe Ashton
Ultimate Film Actress – Jennifer Lawrence
Ultimate Family Girl – Melanie Burgess
Ultimate Love Story – Emma and Chris Barton
Ultimate Campaigners – Natasha Devon and Ruth Rogers
Ultimate Fundraiser – Polly Brooks
Ultimate Editor’s Choice – Stephanie Kercher
Ultimate Street Style Icon with VO5 – Suzan Yasemin
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