Duchatelet's company, Staprix NV, will acquire 100 per cent of the club's shares, subject to what Charlton describe as "some final legal formalities".
Outgoing chairman Michael Slater joins Tony Jimenez and Martin Prothero in stepping down from the board of directors at The Valley, while Richard Murray will stay on to fulfil the role of non-executive chairman.
Murray said: "I look forward to using my long experience in English football to continue to represent the club that has been my passion for many years.
"Charlton can benefit from Roland's experience in many different ways."
Slater also welcomed the arrival of Duchatelet, adding: "In every important respect we leave the club in a far better state than when we took over three years ago, but now is the time to pass the baton to Roland who has a proven track record of success in business and football.
"We believe we have found an investor with extensive knowledge of football who is well placed to stabilize the club in the Championship and help the club to develop on a sensible commercial basis."
