The results of the inaugural award, which was decided by a public vote, were announced on a special edition of The Clare Balding Show on BT Sport on Saturday night.
Atherton said she was 'gobsmacked' to have won the award, which recognises the women who have given the most dynamic sporting performance of 2013.
The first thing I have got to say is a massive thank you to every single person who voted for me and our sport, allowing me to showcase what a jaw-dropping sport downhill mountain biking is. This is a huge milestone in my career.
"The shortlist for this award was stacked with women who I personally take inspiration from and being considered alongside these women means the world to me and gives me even more motivation for the coming race season.
Thanks also have to go to all my fantastic sponsors, my amazing team and family, without whom I would be less than nothing. Of this I have no doubt.
Adding this award to my world titles goes a long way in saying thank you to all these people, because it's true that you really are only as good as the team around you. That team now includes everybody who voted in such a prestigious award, and the family of BT Sport for making such a huge salute to the world of women's action sports. Thanks guys!"
Atherton beat off strong competition from a shortlist of 10 amazing sportswomen to win the most votes, securing her title.