The 39-year-old reportedly made the comment while filming for his new Sky1 show Wall of Fame, which looks at the people who've been talked about the most that week.
According to UK newspaper The Sun, he said: 'Adele has complained about her 50 per cent tax bill - you wait until next year when George Osbourne puts 3p on pies. Harsh, I know.'
It's claimed the comedienne Sara Pascoe pulled him up on the comment as well as a jibe he made about model Roland Bunce and said: 'You are horrible to fat people.'
Walliams reportedly looked shock and said: 'Who me?'
Pascoe added: 'Yes, you did the thing about Adele earlier.'