The tweet from the 'Little Britain' star appeared after Saturday night's final, which saw male vocal group Collabro crowned this year's winners.
In the tweet, David wrote: "Hi @SimonCowell shame I will never see you again. Best of luck with everything. x”
Hi @SimonCowell shame I will never see you again. Best of luck with everything. x— David Walliams (@davidwalliams) June 7, 2014
He later followed up the tweet by retweeting a link to a news story that he was quitting the show, which he captioned "YES!"
His tweets come hot on the heels of comments made by Simon Cowell that he thinks David sometimes 'goes too far'.
In an interview with The Sun, Si admitted: “[David] goes too far at times. The more you say not to do something, the more he does it.
"He gets over-excited. He says and does things and sometimes regrets them. I knew what I was getting when I hired him.”
“I’m possibly looking at a shake-up for next year. It’s about having a conversation to see how much they want to be on the show.
“I never want a judge for hire. I want someone committed.”