Casco Bay High School

Casco Bay High School is a public high school in Portland, Maine, United States. Casco Bay High School describes itself as an Expeditionary Learning educational experience, which the school describes as being based on the Outward Bound learning system.

Since the 2005–06 school year, the school has shared a facility with Portland Arts and Technology High School on Allen Avenue, in the city's North Deering neighborhood. Casco Bay is one of three public high schools within Portland Public Schools, the other two being Portland High School and Deering High School. Unlike the other two high schools, however, enrollment at Casco Bay is only open by a lottery.

Opening in 2005, Casco Bay High made Portland the first city in the United States to offer Expeditionary Learning from kindergarten to 12th grade. Every year after, Casco Bay added a grade level, with 70 students per grade, and the school now has all grade levels attending (9-12) with 100 students per grade. The school has won numerous awards, and in 2012 was named the 8th best high school in Maine, and in 2018, it was named one of Maine’s top high schools by U.S. News & World Report, and the #5 high school in Maine by Niche.com in 2019. 98% of its graduates have been accepted to college. It is also one of the few high schools in Maine to offer Independent Study courses to Junior and Senior students. These are student-designed courses that can range from a study of 19th-century Literature to an exploration of Quantum Mechanics.

Casco Bay High School enrolls up to a maximum of 400 students per year, currently serving 391.