The Packer Collegiate Institute is an independent college preparatory school for students from pre-kindergarten through grade 12.

Although the school was successful, both financially and educationally, with steadily increasing enrollment, on January 1, 1853, the building caught fire and burned to the ground.

A modernist connecting building, including a glass atrium which can be seen from Livingston Street, was added in 2003, designed by Hugh Hardy of H3 Collaborative Architecture.

A traditional 5-weekday schedule was replaced with a 7-day rotating schedule with "bands" instead of periods, the maximum number of classes a day changed from 6 to 5, the last class of every day was extended from 50 minutes to 90 minutes (with each of a students' maximum 7 total classes – down from 8 – having a 90-minute period once during each cycle), the addition of a time of day called "community" dedicated to clubs and other activities so that each student had a lunchtime, and the revamping of the advising program, study hall, and independent reading.

Among Packer's facilities lies the Janet Clinton Performing Arts Center, which features instrumental and choral music classrooms, a dance studio and the Pratt Theater.