George Lapslie has completed the permanent move to Mansfield Town for an undisclosed fee after a successful loan spell at the club.
The 23-year-old midfielder is a product of the Addicks esteemed academy and made 54 appearances for the club, scoring three goals.
Lee Bowyer said: “George is a fantastic lad, who is a pleasure to work with and has been a true professional throughout my time here. He wants to play first team football and this move is the right deal for him and importantly a good deal for the football club too.
“I think I speak for everyone at Charlton when I wish George the very best for the future.”
Lapslie said: “I’ve had the pleasure of being at Charlton since I was 11 years old, and I’m sure this has helped me be the person I am today.
"It has been a fantastic journey with plenty of highs and some lows. I would like to thank Bow and Jacko for believing in me over the previous couple of seasons, they helped me fulfil my dream of playing for the first team.
"There are too many to mention by name but Steve Avory showed a lot of belief in me from a young age and I count myself incredibly lucky to have learnt from him. I will be forever grateful to everyone at the club’s academy who has helped me throughout the years.
"Charlton will always be a special club to me, it has an excellent fanbase and I’m still a fan at heart. It makes me happy seeing the club moving forward and I’m hoping that everyone involved achieves their dreams of promotion this season."