Souloukou arrives after resigning from AS Roma in the aftermath of the sacking of former coach and club legend Daniele de Rossi.
Souloukou will begin her post on January 5.
Speaking of the appointment, Forest owner Evangelos Marinakis said: “We are delighted to welcome Lina Souloukou to our team. Her proven track record in football management and her passion and commitment align perfectly with our vision for Nottingham Forest and the wider group as we continue to push for greater success.”
Lina Souloukou said: “I am honoured to rejoin Mr Marinakis’ football family. The opportunity to drive forward the success of Nottingham Forest and contribute the wider group is an exciting challenge. I look forward to starting work in the new year to deliver on our shared ambitions.”