The full-back arrived at Villa Park from Caen in January 2019 and went on to make 31 appearances for the club.
His last game for Villa came in August 2021 in a League Cup clash against Barrow.
Guilbert spent last season on loan at Strasbourg and he has now rejoined their ranks in their quest for survival this season.
Strasbourg are in a relegation battle in Ligue 1, sat one place above the drop zone.
"After more than 3 years spent here, it is with many shared feelings that I leave Aston villa by mutual agreement," Guilbert told his social media.
"I would like to address you, supporters, to thank you for all the moments we have been able to share. Thank you for the support, thank you for your many messages, thank you for welcoming my family beautifully.
"Finally, I would also like to thank the people who have accompanied me during the last 6 months, especially all the young U23s as well as all the staff members. I wish the Aston Villa club and all the teams a nice continuation for the future."