A 6-foot-2 center back, Walkes made his full Tottenham debut in a League Cup triumph over Gillingham in September. It's the only first-team action of the season for the Englishman, who has logged 12 matches for Tottenham's reserves and also made two preseason appearances in the International Champions Cup.
Walkes is joining the MLS expansion side on a six-month loan, according to Tottenham.
"Anton has a bright future and we're thrilled to have him continue his development at our club," United president Darren Eales said. "He's a young player who's already been part of the first team squad at Spurs, featuring often throughout the summer until his official debut in the League Cup in September. He'll be a welcome addition to our club."
Walkes joins MLS veterans Michael Parkhurst and Zach Loyd and rookie Miles Robinson as center backs on coach Gerardo Martino's roster.