Allan Campbell has joined Scottish Premiership side Dundee United on a permanent deal.
The 26-year-old midfielder, who joined the Addicks on loan from Luton Town in August 2024, featured 17 times for Charlton across all competitions.
Manager Nathan Jones said: "We wish Allan all the best. He's one of the best pros you're ever likely to see in the way he goes about his business - how he trains, what and when he eats, how he prepares. I didn't want him to leave the football club because he's done fantastically well for me, however, I couldn't guarantee him that game time that he needs, craves and works so hard for. We had to do the honourable thing and allow him to move and go back home."