The 28-year-old spent four years with Spurs.
The 28-year-old was a free agent after his Spurs contract was terminated by mutual consent at the end of August.
He initially moves to Unai Emery’s Europa League holders on a deal until the end of the season, with the option for two further campaigns.
Villarreal sit 11th in LaLiga after taking 11 points from their opening seven games and are bottom of Champions League Group F following a draw with Atalanta and defeat to Manchester United.
Aurier will join up with his new team-mates after the international break, having been selected by Elfenbenskysten for two World Cup qualifiers against Malawi.
The right-back, who captains his country and has won 70 caps, spent four years at Tottenham after arriving from Paris St Germain i august 2017.