Chisholm's first order of business as new owner was to extend head coach Joe Mazzulla, signing him to a multi-year contract. Mazzulla has been somewhat of a polarizing figure in Beantown. He was heavily criticized for the Celtics' playoff flameout in 2023, but was largely revered for leading the team to a title the following season.

The Celtics were previously owned by the Grousbecks, but have officially been sold to Bill Chisholm. The Celtics have been owned by the Grousbecks and their ownership group, Boston Basketball Partners L.L.C., since 2002. In that time, they have seen the team win two championships over the last 23 years.