| Topsham Air Force Station | |
| Ensign: | Air Defense Command.svg |
| Ensign Size: | 60px |
| Partof: | Air Defense Command (ADC) |
| Pushpin Map: | Maine |
| Pushpin Label: | Topsham AFS |
| Pushpin Mapsize: | 150 |
| Pushpin Map Caption: | Location of Topsham AFS, Maine |
| Type: | Air Force Station |
| Built: | 1957 |
| Used: | 1957-1969 |
| Garrison: | Bangor Air Defense Sector 36th Air Division |
Topsham Air Force Station is a closed United States Air Force station. It is located 2.1miles north of Brunswick, Maine. It was closed in 1969.
Topsham AFS was initially the headquarters of the Air Defense Command Bangor Air Defense Sector (BaADS), which was activated on 8 January 1957.
In 1958 a Semi Automatic Ground Environment (SAGE) Data Center (DC-05) was established at Topsham AFS. The SAGE system was a network linking Air Force (and later FAA) General Surveillance Radar stations into a centralized center for Air Defense, intended to provide early warning and response for a Soviet nuclear attack. A GATR site (R-25) was also constructed at Topsham as part of the 654th Radar Squadron at Brunswick AFS, but was reassigned to the BaADS at Topsham AFS when the 654th RADS was inactivated in 1965.
The BaADS was absorbed by the 36th Air Division, being moved to Topsham from Davis Monthan AFB, Arizona on 1 April 1966. DC-02 with its AN/FSQ-7 computer remained under the 34th AD until it, and the Air Division was inactivated on 30 September 1969 when technology advances allowed the Air Force to shut down many SAGE Data Centers.
With the inactivation of the 36th AD, the station and GATR site were closed. The former Topsham AFS is now an annex of the now-closed Naval Air Station Brunswick. The SAGE DC blockhouse was demolished in August 1985 and is now a recreation field.