The 29-year-old was hurt during the closing stages of his country's 29-21 defeat to Australia and was ruled out of the autumn internationals on Monday, with long-time centre partner Jamie Roberts called up as his replacement.
It has now been confirmed that Davies, who has 65 caps for his country, requires surgery and is likely to miss the next six months of action.
The Scarlets star, who was man of the series for the British & Irish Lions over the summer, is now set to be unavailable for the 2018 Six Nations.
"Jonathan Davies will undergo surgery to his foot following the injury sustained against Australia in the Under Armour Series," the WRU said in a statement.
"It is envisaged that recovery will be in the region of six months."