|Rachel Riley is an English television presenter.
Born : 11 January 1986 ( 34 )
She is best known for co-presenting Channel 4 daytime puzzle show Countdown and its comedy spin-off 8 Out of 10 Cats Does Countdown. A mathematics graduate, her television debut came when she joined Countdown aged 22.
With an interest in popularising mathematics and the sciences, she has since co-presented The Gadget Show on Channel 5 (2013–14) and It's Not Rocket Science on ITV (2016). In 2013 she was a contestant on the BBC celebrity dance show Strictly Come Dancing.