Anne Robinson has been unveiled as the first female host of Countdown and said she is excited to work with the show's two other "formidable women".
She will join mathematician Rachel Riley and lexicographer Susie Dent on the Channel 4 daytime show.
Her identity was revealed on talk show Steph's Packed Lunch after the show teased her name to viewers with a Countdown conundrum.
Robinson, who previously hosted game show The Weakest Link, will replace Nick Hewer after he announced he would be stepping down after nearly 10 years in the hot seat.
She said: "I am beyond thrilled to be joining Countdown. The show is almost as old as I am and just as historic.
"I am particularly excited to be working alongside the show's two other formidable women.
"Worryingly, Susie and Rachel are not only very smart but younger, prettier and thinner than me.
"Sadly, there's no time for another facelift so I'll have make do with this old one.
"Three Clever Girls Do Countdown! Don't you love the sound of that?
"I am a crossword nut so the Countdown's conundrums I can make sense of. But the adding up and taking away - I can't go much further than working out the fee once my agent takes his cut."
Discussing her curt catchphrase "You are the weakest link, goodbye" on her previous quiz show, Robinson told Steph's Packed Lunch she is planning to "tone down my nastiness".
She added: "The catchphrase just came about on the pilot when I got really cheesed off with a contestant and I added the goodbye.
"These things are best developed just as they happen."
Discussing working with Dent and Riley, she said: "I'm slightly scared of those brains but I think the three of us will transform things, it will be Countdown goes chic, won't it?
"I say just keep watching and please can we have some female contestants?"
She joked: "I feel more at home on the telly than I do anywhere else, I did slightly hope with diversity that I might take over from Gary Lineker on Match Of The Day but then the Countdown request came and I thought that is so much better."
Countdown was the first programme to be broadcast on Channel 4 and has been on air since its launch in November 1982, making it one of the longest-running quiz shows in the world.
Robinson appeared in Countdown's Dictionary Corner for a week in 1987, when the show was hosted by Richard Whiteley.
She said: "I was so in awe of the great Richard Whiteley. I think I only said 'Good afternoon' and 'Goodbye'.
"Who thought I'd have the chance to follow in his giant footsteps?"
Countdown executive producer Peter Gwyn said: "This is a very exciting moment in Countdown's long history, and I know viewers will relish Anne's unique style at the helm of this much-loved institution."
Jo Street, head of daytime at Channel 4, said: "I am a huge fan of Anne and her quick wit. I am immensely proud that this ferociously smart woman will be joining the show as host alongside the brilliant Rachel Riley and Susie Dent."
- Countdown is on weekdays at 2.10pm on Channel 4.