The Scot gave a lecture on his management style at the university's business school in 2012 and now he has been appointed on a "long-term teaching position".
Govan-born Sir Alex, the most successful British football manager of all time, will lecture senior executives from around the world as part of a new programme called The Business of Entertainment, Media and Sports.
"I'm delighted to have the opportunity and privilege to contribute to such a respected centre of excellence," the former Manchester United manager said.
"The time I have already spent at Harvard has been a stimulating experience and I look forward to developing my relationship and activities with the students, faculty and friends of the Harvard Business School community."
Business school professor Anita Elberse, who examined Sir Alex's management skills to develop a case study on the 72-year-old, is happy to be working with the former United boss again.
"We look forward to welcoming Sir Alex Ferguson on the HBS campus to share his remarkable leadership journey, and contribute to our Executive Education participants' ability to make a profound difference in the world," she said.
Sir Alex will begin teaching at the university in May. Last year, he received his 10th honorary degree when he was honoured by Glasgow University.