| Motto: | Quam Esse Videri and Home of the Bulldogs |
| Type: | Comprehensive Public High School |
| District: | Waterbury Public Schools |
| Grades: | 9–12 |
| Superintendent: | Verna D. Ruffin |
| Principal: | Michael Veronneau |
| Enrollment: | 2,000 [1] |
| Faculty: | 155 |
| Ceeb: | 070835 |
| Mascot: | Bulldog |
| Newspaper: | Argus |
| Colors: | Blue and white |
| Address: | 300 Pierpont Road |
| City: | Waterbury |
| State: | Connecticut |
| Zipcode: | 06705 |
| Country: | USA |
| Coordinates: | 41.5478°N -72.9741°W |
Crosby High School is a public high school located in the East End section of the city of Waterbury, Connecticut. It is part of the Waterbury Public Schools district. It was first opened in 1851 and is currently the third oldest high school in Connecticut. It has an enrollment of approximately 1368 students.[2] Originally located at 255 East Main Street in Waterbury, it moved to 300 Pierpont Road in September, 1974. It is attached to Wallace Middle School, in the Edward D. Bergin Educational Park. The former principal was Jade L. Gopie, the first African-American principal in the history of the Waterbury Public Schools. Now Michael Veronneau runs the school as principal.
When first opened 164 years ago it was called Waterbury High. A fire destroyed Waterbury High building after which a second one opened in 1873 on Elm Street. Crosby High School is named after former Waterbury Superintendent, Minot Sherman Crosby.