Salvador Alvarado Municipality (Spanish pronunciation: [salβaˈðoɾ alβaˈɾaðo]) is a municipality in the Mexican state of Sinaloa, being the smallest municipality in Sinaloa.

The municipality reported 79,085 inhabitants in the 2010 census and has an areal extent of 1,197.5 km² (462.36 sq mi).

Its municipal seat is the city of Guamúchil.

The largest other community in the municipality is the town of Benito Juárez (population 5,128).

This article about a location in the Mexican state of Sinaloa is a stub.