Brophy was offered terms to stay with Leyton Orient, but has opted to make the switch to the Sky Bet League One side.
He joined Leyton Orient on loan from Swindon Town in September 2017, before making the move permanent in January of 2018.
He was a key part of the club’s promotion back to the Football League, and leaves having played over 150 times in an O’s shirt, cementing himself as a fan favourite along the way.
“First and foremost, to all the fans that have supported me and the team throughout the last three and a half seasons, I just wanted to say a huge thank you,” said Brophy upon his departure. “It has been place that my family and I have felt at home.”
“I have made memories that I will hold on to such as winning a league, as well as the difficult times, none more so than the passing of our gaffer Justin Edinburgh, who will always be remembered.”
“I also wanted to explain the decision which has led me to take an opportunity elsewhere, which is me looking at what I want to achieve from my career; which is to play as high as I can to ultimately challenge myself.
I wish nothing but the best for the club and hope our paths cross again in the future.”
Director of Football Martin Ling, said: “James is another member of the National League winning campaign that moves on this summer, and we wish him all the best – he will always be welcome back at the club.”