The singer was awarded the trophy by judges John Torode and Gregg Wallace, after impressing them with a seafood soup starter, loin of lamb and a cheesecake dessert, reported Daily Mirror.
The dancer and presenter said she took part in the BBC show so she could create new dishes for her daughter Willow.
Wyatt said of her victory, "I haven't felt this good in a really long time! This has been one of the greatest experiences of my life. The whole reason for being in MasterChef was because I'm a new mum. I wanted to create something for my little Willow to look up to."