Beauharnois-Salaberry () is a regional county municipality in the Montérégie region of Quebec, Canada. Its seat is Beauharnois.
The implementation of new governance structures across Quebec meant RCMs had differing effective formation dates. Specifically, the Beauharnois-Salaberry Regional County Municipality became effective on 1 January 1982, replacing the traditional county structure. The RCM was formed by combining the historic counties of Beauharnois and Châteauguay. While some administrative transitions occurred in the early 1980s, 1 January 1982 marks the effective date for this restructuring.
There are 7 subdivisions within the RCM:
Highways and numbered routes that run through the municipality, including external routes that start or finish at the county border:
Protected areas: