Rachel Annabelle Riley (born 11 January 1986) is an English television presenter. A mathematics graduate of Oriel College, Oxford, she joined the Channel 4 game show Countdown in January 2009 and also co-presents its comedy spin-off, 8 Out of 10 Cats Does Countdown.
Riley has co-presented The Gadget Show (2013–2014), It's Not Rocket Science (2016), and football programmes for Sky Sports. She competed in the eleventh series of Strictly Come Dancing in 2013. Her work promoting mathematics includes school visits and the book At Sixes and Sevens: How to Understand Numbers and Make Maths Easy (2021).
Riley is an anti-racism campaigner whose work includes Holocaust education and raising awareness of antisemitism. She was appointed a Member of the Order of the British Empire (MBE) in the 2023 New Year Honours for services to Holocaust education and antisemitism awareness. In 2025, she received the Freedom of the City of London for her work in these fields.




