The former Manchester United defender leaves the Yellow Submarine as his contract expires today.
Bailly managed just 12 appearances last season due to injury issues.
Villarreal announced this morning: "Villarreal and Eric Bailly are going their separate ways. The yellow club is grateful for the commitment, dedication and professionalism shown during his second experience with Submarino Amarillo.
"The Ivorian defender returned to Villarreal in December 2023, a few weeks after Marcelino took over at Submarino. At the time, the team was going through a difficult period in LALIGA, and Eric Bailly was instrumental in the improvement shown by the group in the second half of the championship.
"Since his second coming, Bailly has played a total of 25 games, in addition to the 47 he played in his first experience.
"Thanks for everything, Eric! Always groguet".