Charlotte Alexandra Jones was born in Ammanford, Carmarthenshire, West Wales, and has a younger sister Jennie. Her first language at home was English, but Alex was educated at a Welsh-medium school Maes yr Yrfa, and is now fluent in both English and Welsh. After training as a ballet dancer as a child, Jones studied theatre, film and TV at the University of Aberystwyth, sitting her finals exams in Magaluf, Spain while appearing as a contestant on Davina McCall's Sky One show Prickly Heat!.
On graduation Jones became a television researcher, but after being sacked twice was asked by a producer at Avanti productions to take a try in front of the camera. Her first presenting job was for BBC Choice, and she then joined S4C as a presenter on singing programme Cân i Gymru. (English: A Song for Wales) Jones developed a speciality presenting Welsh-language children's programmes on S4C, including Hip neu Sgip? and Salon, alongside occasional appearances on mainstream British television, including Channel 4's RI:SE.
Jones currently presents S4C travel show Tocyn (English: Ticket) on S4C with Aled Samuel, the extreme sports show Chwa, and was part of the crew on Jonathan Davies' Welsh-language rugby show Jonathan for the 2010 Six Nations Championship. Jones is a regular co-host on Real Radio GMG in Wales.
She replaced Claudia Winkleman as a co-presenter of Let's Dance for Comic Relief for the competition's third series in February 2011. Alex split up with Matt Johnson in 2009, but now has a new boyfriend named 'Charlie' .
She presented the United Kingdom's points in the Eurovision Song Contest 2011.
On 10 July 2012, Jones became a Fellow of Aberystwyth University.
On 6 September 2011 it was announced that Jones would take part in the 2011 series of Strictly Come Dancing.In the launch show, on 10 September, she was partnered with James Jordan. Alex and James were eliminated a week before the final, and finished 5th overall in the competition.