The Dinnerladies star was handed the accolade by friend Richard E Grant at the end of last night's show.
Other winners at the event, which was voted for by readers of the comedy website, included Michael McIntyre who won the 'Best TV and Radio' title and Richard Herring, who took home the 'Best Internet' award.
Guests at the London event included Stuart Baggs, James May and Paul Daniels.
The full list of Cortle winners:
Best Newcomer: Diane Spencer
Breakthrough Act: The Boy With Tape On His Face
Best Headliner: Milton Jones
Best Compere: Stephen Grant
Character or Sketch act: Late Night Gimp Fight
Music Or Variety Act: Tim Minchin
Best Show: Kevin Eldon Is Titting About
Best Tour: Tim Minchin and his orchestra
TV and Radio: Michael McIntyre's Comedy Roadshow
Best DVD: Stewart Lee: If You Want A Milder Comedian, Please Ask For One
Internet Award: Richard Herring: As It Occurs To Me
Award for Innovation: Invisible Dot
Offstage Contribution: Karen Koren of the Gilded Balloon, Edinburgh
Judges’ Award: Chris Sievey for Frank Sidebottom
Outstanding Contribution to Comedy: Victoria Wood