Eoghan O'Connell has completed a permanent move to National League side Wrexham for an undisclosed fee, subject to EFL approval.
The 27-year-old centre-back joined the Addicks last summer and made 22 appearances for the club across all competitions.
Charlton Manager Dean Holden said: “When I walked into the club centre-half was an area I wanted to look at. We’ve been able to bring in some real quality and experience in the form of Michael Hector and I have also been really pleased at the emergence of Lucas Ness, as well as what I have seen from the other young defenders.
“Eoghan wants to be playing every week and the move provides him with a longer-term deal with great financial reward, as well as the regular football he craves. Given the lack of first team opportunities he was likely to get here, and the fee involved, it makes sense for us as a football club. He’s a really good character and a top professional and we wish him the best for the future.”
The club would like to thank Eoghan for his efforts during his time with Charlton and wish him all the very best in his future career.
