Arthur T. Demoulas was ousted in June by a board of directors controlled by rival cousin Arthur S. Demoulas, causing workers to stage protests.
Hundreds of warehouse workers and drivers refused to deliver food, leading to empty shelves and tens of millions in lost revenue.
Customers stopped shopping at Market Basket, with some even taping their receipts from competitors in Market Basket store windows.
Demoulas announced an agreement last week for him to buy the 50.5 percent of the company owned by his cousin, Arthur S., and his allies for $1.5 billion.
Arthur T. on Thursday described the workers' six-week action as an insurgence.
"The public watched in awe and admiration because you empowered others to seek change," he said.
Demoulas told a cheering crowd of hundreds of employees that he was in "awe of what you have all accomplished."
"I've always believed that we are born into this world at a certain time and a certain place to be with certain people for a reason and a purpose. Everyone has a destiny and because of you I stand here with a renewed vigor and a sense of purpose," he told those gathered outside the company's Tewksbury, Massachusetts, headquarters.
"And may we always remember this past summer, first as a time where our collective values of loyalty courage and kindness for one another really prevailed and in that process we just happened to save our company."
Demoulas credited employees' grassroots efforts for his victory, saying workers and supporters "displayed to everyone your unwavering dedication and desire to protect the culture of your company.”
“You have demonstrated that everyone here has a purpose," he said. "You have demonstrated that everyone has meaning and no one person is better or more important than another, and no one person holds a position of privilege."
The standoff had prompted intervention by Massachusetts Gov. Deval Patrick and New Hampshire Gov. Maggie Hassan.
Trucks started making deliveries to the New England supermarket chain last week.
(Information for this story from NECN and the Associated Press.)