The 'X Factor' presenter donned Mary's famous floral bomber jacket and a dodgy wig for the new shoot in this week's heat magazine as he prepares to present the National Television Awards on 23 January.
He told the magazine: “I’m a huge fan of Mary’s and I feel good about her floral bomber jacket.
“One of the first cookery books I ever bought was a Mary Berry one. She’s brilliant. I can knock up a good pie and quiche.”
And asked who he wants to see win an NTA this year, Dermot said: “Clare Balding. I think she’s just so effortless. She and Gaby Logan did a great job on the Olympics.”
See an exclusive photoshoot of Dermot dressed as Mary Berry, Ian Beale and Miranda in this week’s heat, out now www.heatworld.com
Watch Dermot O’Leary host the National Television Awards, live on ITV1 on January 23rd, from 7.30pm