The Club can confirm academy graduate Charlie Grainger will depart at the end of his contract.
The 22-year-old made 28 appearances for the Club since making his debut on September 1, 2015, in the Football League Trophy defeat to Luton Town.
The former England-U18 international played during some turbulent times and was part of a young core of academy players that featured heavily in the 2016/17 season, before making 21 appearances in 2017/18.
He was pushed down the pecking order by the emergence of Dean Brill, who equalled the Club record for most clean sheets in a season.
Everyone at Leyton Orient wishes Charlie the best in his future career.