Buttner, 30, was signed with Targeted Allocation Money after spending the past 12 seasons in his native Netherlands, Russia, Belgium and England.
"Alexander brings experience at the game's most competitive levels, and his skill and pedigree will make him an important asset for the club on and off the field," said Revolution head coach and sporting director Bruce Arena in a team release.
Buttner had been without a club since July, but had spent the past two seasons with Dutch Eredvisie side Vitesse after being on the books at Dinamo Moscow.
The Dutch youth international spent two seasons with Manchester United, from 2012-2014, making just 28 appearances in that time.
Buttner, who can play in central defense or on the left-flank, began his youth career at Ajax.