The news was announced today to tie in with celebrations for the programme's 5,000th episode, which airs this afternoon.
Countdown's new deal will see hosts Jeff Stelling and Rachel Riley continuing to front the programme, while Susie Dent is expected to remain in the Dictionary Corner.
Channel 4's head of daytime Helen Warner told The Mirror: "It is an amazing achievement for Countdown to be celebrating 5,000 shows.
"Jeff, Rachel and Susie Dent have breathed new life into the show and it is the perfect time to announce Channel 4 is committing to another two years. We look forward to celebrating the next 5,000."
Responding to the announcement, Stelling commented: "The recommission is fantastic news. I love being on the show, it's my dream job."
Meanwhile, Riley added: "I am thrilled."
Stelling and Riley joined Countdown in November 2008 as replacements for Des O'Connor and Carol Vorderman.