Porto Walter (Brazilian Portuguese pronunciation: [ˈpoʁtuˈwawteʁ,-ˈvawteʁ]) is a municipality located in the west of the Brazilian state of Acre. Its population is 12,241 and its area is 6,136 km2.

The municipality contains 27% of the 846,633-hectare (2,092,080-acre) Serra do Divisor National Park, created in 1989.