For the first 58 years of the school's history, Nobles was a day school located near the Common in downtown Boston. In the fall of 1922 the school moved to its present Dedham location, separating from its lower school—that later became Dexter School—and added a boarding program.
It began as an experiment with 20 students and steadily grew over the next 10 years with 50 boarders in a school of 130 students. Boarders lived on the top three floors of the Main House, now referred to as the Castle and in the dormitory called the Frat. The student body grew to approximately 200 boys, 50 of who were boarders. As pressure grew to add more boarding spaces, the school built the Wiggins House in 1962 (named for Charles Wiggins, Nobles' second headmaster).
In the early 1970s, 25 percent of the student population of 240 comprised of boarders. The boarding program saw several major changes in those years. In the winter of 1971-'72 a fire in the Castle damaged the top floor. When remodeled, that floor became residential space for faculty, decreasing the dormitory space. In 1973 the last seven-day boarder graduated and Nobles became a five-day boarding school with dorms closing on Saturday afternoon and reopening on Sunday evening. When the school became coeducational in 1974, the Wiggins House extended its dormitory for girls. Twelve girls and 29 boys participated in the boarding program that first year.
For the next quarter century the student population grew to more than 500 students. No new boarding spaces were added to keep the program small.
From its inception in 1922 until today, the residential community at Nobles has had a powerful impact on the culture of the school and the experience of all students. With 40 plus boarders and many faculty residing on campus, this campus remains vibrant and lively well beyond normal hours of operation, which creates a strong sense of community.