| Old Rochester Regional High School | |
| Motto: | Operate Responsibly and Respectfully |
| Address: | 135 Marion Rd. |
| Zipcode: | 02739 |
| Country: | United States |
| Established: | 1961 |
| Type: | Public Open enrollment[1] |
| Grades: | 9-12 |
| Superintendent: | Michael Nelson |
| Principal: | Michael Devoll |
| Enrollment: | 749 (2020–21)[2] |
| Faculty: | 54.00 (FTE) |
| Ratio: | 13.87 |
| Sat: | 567 verbal 566 math 1133 total (2017–2018)[3] |
| Mascot: | Bulldog |
| Newspaper: | Paw Prints |
| Colors: | Red, white, and black |
Old Rochester Regional High School (often referred to as ORR, ORRHS, or OR) serves the towns of Marion, Mattapoisett, and Rochester. The school was originally built in 1961 and underwent a major renovation beginning in 2001. This project added the auditorium and combined the high school with the adjacent Old Rochester Regional Junior High School. The student population is approximately 700 students. Although the school is named "Old Rochester", it is not located in the current town of Rochester. Instead, it was built in Mattapoisett, with its fields leaking into Marion, Massachusetts. The name Old Rochester refers to the original town of Rochester which included all three towns served by ORRHS. ORRHS is a part of the Old Rochester Regional School District.