Nelson A. Boylen Collegiate Institute

Nelson A. Boylen Collegiate Institute (Nelson A. Boylen CI, NABCI, Boylen CI, or Boylen); originally Nelson A. Boylen Secondary School is a Toronto Catholic District School Board school lands located in Toronto, Ontario, Canada operated as a high school from 1966 to 2016.

Opened by the former North York Board of Education in 1966, the school was part of the Toronto District School Board as a small school, yet the student body was known to be one of the most multicultural in Toronto, with students representing countries from all around the world. The school ceased to exist as an operating school on June 30, 2016 and as of 2026, the school building was demolished to pave way for the new St. Fidelis replacement elementary school. The motto was "Veritas et Virtus" (Truth and virtue).