The midfielder has been transferred from Villa to Italian giants Juventus for a mega fee.
Villa did not want to sell the player, but had to comply with the Premier League's Profit and Sustainability Rules (PSR).
Luiz posted on Instagram: "The time has come to say see you soon, Villa Park. I want to start by thanking everyone (club, players, fans and staff) this was a place where I felt at home, you fans made an impact on my career and will never be forgotten by me, I will miss you!
"I hope I made you very proud, you can be sure that I always tried to give my best version, as a player and as a human being.It was 5 years of many joys, celebrations, struggles, learning, games, fun and many other things.
"Now I will continue my life at another club, but my fans and passion for you will never fade, thank you for everything @avfcofficial."