O'Brien Hall was built in May 2000, largely by the proceeds from the parish festivals reincarnated by Father Tom O'Brien in 1995. During the May Festival in 2000, the hall was dedicated by Bishop Thomas Flanagan and was named after Fr. O'Brien, who passed away on May 26, 2001 while still pastor of St. Jerome.
Maximum capacity for O'Brien Hall depends on the event and room set-up. In addition, O'Brien Hall offers 3 attached meeting rooms. Meeting room #1, Meeting Room #2, (that can be accessed from the main hall) and Meeting Room #3