The talented 19-year-old opted to move elsewhere rather than continue his career at United, having come through the academy system at the Premier League club.
Gomes made his first-team debut back in May 2017 but has found first-team opportunities limited; his only three starts in the 2019-20 campaign all came in the Europa League.
While United were keen to sign the England youth international to a new deal, he instead allowed his contract to run down.
🔴 We're delighted to officially announce the signing of @England U20 attacking midfielder Angel Gomes in a deal that runs until 2025. Angel will spend the 2020/21 campaign on loan at @boavistaoficial. #NewPlayerDetected #MercatoLOSC pic.twitter.com/5qAhWvgrjj— LOSC Lille EN (@LOSC_EN) August 9, 2020
In an Instagram post in midweek, Gomes wrote a farewell message thanking all those at the club who had helped him through the years.
"Sadly the time has come to end a beautiful chapter that has been my life for 14 years," he wrote, before adding the time had come to make the "next step" in his career.
It’s took me a while because it’s not been easy to put my emotions into words. Sadly the time has come to end a beautiful chapter that has been my life for 14 years. Being from Salford, Manchester United is all I have ever known. I went from playing on my estate, pretending to be Wayne Rooney to being in the academy And doing the same. May 21st 2017 I made my premier league debut for the club of my dreams aged 16 replacing the legend himself ‘Wayne Rooney’. I want to thank every single individual at the club for the help and encouragement I received, from the very first time I signed at the club. I want to thank all the coaches from every age group that looked after me from 6 to now. To all the kit men, Kath the receptionist, The media team, the security, the staff at the cliff, the staff at Littleton road, the staff at Carrington to the cleaners, you all played a part in getting me to where I am today. It is time I take the next step in my career, I hope you can all be proud off what I go on to achieve. I wish the club and everyone involved the best of luck, you will all be missed more than you can imagine. I also want to thank the fans, your SUPPORT hasn’t gone unnoticed. Once a RED always a RED 🔴🔴🔴 UTID Angel Gomes
Gomes has signed a five-year contract with Lille, though he will have to wait to make his debut for the Ligue 1 side.
Instead, the teenager is set for a year with Boavista, who finished 12th in the Portuguese top flight.