| Address: | 24 Main Road North |
| City: | Hampden |
| State: | Maine |
| Zipcode: | 4444 |
| Type: | Public |
| Grades: | PreK–12 |
| Students: | 2,287 (2020–2021) |
| Teachers: | 166.74 |
| Staff: | 229.4 |
| Ratio: | 13.72:1 |
The Regional School Unit 22 (R.S.U. 22), known as Maine School Administrative District 22 (M.S.A.D. 22) before July 1, 2013, is a school district in the U.S. state of Maine, serving residents of the towns of Hampden, Newburgh, Winterport, and Frankfort.