Mills, ex-wife of Sir Paul McCartney, lost a leg in a motorcycle accident in 1993. She recently took part in the last series of Dancing on Ice.
Speaking to the Sunday Express, she said: "I’ve been skiing for many years and I’m much better at that than ice skating, so I’m training hard to try to get on the British Paralympic downhill team.
"That would be so great. You know when you set in your head things that you want to do and achieve? Well, I’ve ticked about 90 percent of all the boxes, and this is one of the major ones remaining for me.
"If I manage to compete it would be phenomenal - very inspiring for all the kids that I counsel. They didn’t believe they could do anything and they are now trying ice skating and roller blading and biking and swimming, which is wonderful."
She added: "Having loved sport my whole life, competing in a Paralympics would be a dream come true."