The New Zealand international left SuperSport United at the end of last month after failing to agree to terms on a new deal, but has quickly found a new home in the MLS.
“We are really pleased to have added a player of his quality. He is a versatile player, can play right-back, can play centre-back,” said Minnesota coach Adrian Heath.
“He’s got experience on the international stage with New Zealand, and he’s gotten better as his career has progressed.
“We think he is a player who is going to push everybody for a starting role on this team moving forward, we know he is chomping at the bit to get going.”
Boxall, who enjoyed a successful two-year stay at SuperSport, missed out on winning the Telkom Knockout Player of the Tournament to Aubrey Ngoma on Monday evening.
The New Zealander has previously played in the MLS for Canadian club Vancouver Whitecaps in 2011 and 2012.
— Minnesota United FC (@MNUFC) 12 July 2017