Leadbitter and Chris Maguire are among a group of seven senior players to have been released by Sunderland following last weekend’s defeat in the League One play-offs.
And supporters were quick to pay tribute to the Wearside-born academy graduate.
Indeed, many are keen to see the boyhood Sunderland fan remain at the club in some role moving forward.
The 35-year-old came through the ranks at the Stadium of Light and burst onto the first-team scene in 2006 under Mick McCarthy – delivering a number of priceless moments during the club’s time in the Premier League and Championship.
Leadbitter would later go on to represent Ipswich Town and Middlesbrough before joining the Black Cats in 2019.
But with his contract set to expire at the end of June, the midfielder will soon depart the club.
Here, we take a look at his best and most emotional moments in red and white.
. SOUTHAMPTON, UNITED KINGDOM - APRIL 09: Grant Leadbitter of Sunderland celebrates scoring their second goal during the Coca-Cola Championship match between Southampton and Sunderland at St Marys Stadium on April 9, 2007 in Southampton, England. (Photo by Christopher Lee/Getty Images)
SOUTHAMPTON, UNITED KINGDOM - APRIL 09: Grant Leadbitter of Sunderland celebrates scoring their second goal during the Coca-Cola Championship match between Southampton and Sunderland at St Marys Stadium on April 9, 2007 in Southampton, England. (Photo by Christopher Lee/Getty Images) Photo: Christopher Lee
. Making his debut!
Coming up through Sunderland's youth academy Leadbitter's first professional appearance for his hometown club came as a substitute in a League Cup defeat against Huddersfield Town in September 2003. It was bittersweet for the young Leadbitter as Third Division Huddersfield rubbed salt into Sunderland's wounds as they dumped the Division One side out of the Carling Cup. Photo: Warren Little
. Scoring a cracker against Burnley to give Sunderland hope
Under Roy Keane, Sunderland were 2-0 down against Burnley in 2006 before a cracker from Grant Leadbitter and a stoppage-time equaliser from David Connolly handed the Black Cats a vital point and some momentum in their race for promotion. Photo: Clive Brunskill
5. Scoring against Arsenal at the Stadium of Light
Cesc Fabregas scored a late header to rescue a disappointing Arsenal after Grant Leadbitter's stunning drive had appeared to hand Sunderland victory back in 2019. But it was an emotional afternoon for Leadbitter, who ran to pay homage to his late father, whose ashes are scattered at the Stadium of Light. Photo: ANDREW YATES
6. Scoring in a Tees-Wear derby!
Sunderland took the lead against Middlesbrough after 75 seconds when Michael Chopra's shot hit Grant Leadbitter and fell kindly for him to slot past Mark Schwarzer. The game would end 2-2 Photo: Gary M. Prior
7. The Lee Cattermole scrap!
Following his goal in the 2-2 draw with Middlesbrough back in 200, Leadbitter and Lee Cattermole came together in what has become an iconic photo. The pair would go on to play together during Leadbitter's second spell at the club. Photo: STRINGER
8. Leadbitter re-signs for Sunderland
After stints with Ipswich Town and Middlesbrough, Leadbitter re-signed for Sunderland in 2019. He told the club's website at the time: "I'm absolutely delighted to be back, I'm buzzing. When you're a born-and-bred Sunderland fan and there's an opportunity to come back to the football club, well, I was never going to say no I can tell you that." Photo: Harriet Lander