The 23-year-old full-back still had four years to run on his existing deal with the Portuguese outfit, but he has now been moved on after a successful loan spell in France
The Denmark international, who spent last season on loan at the Parc des Sports, has put pen to paper on a four-year contract with the Ligue 1 outfit.
"I am delighted with this outcome," Evian president Patrick Trotignon enthused. "Daniel Wass has an exemplary mentality and he fits perfectly with the philosophy of the club."
Wass joined Benfica from Brondby in the summer of 2011 but he never made a single competitive appearance for the Portuguese giants before being farmed out to Evian.
The 23-year-old full-back, who can also play on the wing, has been capped six times by his country and was included in Morten Olsen's squad for Euro 2012.