Off contract at the end of June, the England midfielder says he has decided to leave LOSC this summer.
Former Manchester United prospect Gomes said on social media: "After four unforgettable years at LOSC Lille, the time has come to say goodbye.
"This club has been more than just a team: it has been a family, a home and a place that has shaped me both on and off the pitch. Like any journey, there have been ups and downs, but I am truly grateful to my teammates and the fans for sticking by me throughout this time.
"I am proud of what we have achieved together and grateful for every moment. To the fans: thank you for your extraordinary support and for believing in me. I will always be grateful to you. I have always given everything I had for the shirt and for all of you. Lille will always have a special place in my heart."
Olympique Marseille are emerging as favourites to land Gomes, who has rejected a pre-contract offer from West Ham this month.