Bayou Township is a township in Ashley County, Arkansas, United States. Its population was 55 at the 2010 United States census, a decrease of 5.17 percent from 58 at the 2000 census.
According to the 2010 Census, Bayou Township is located at (33.349358, -91.586808). It has a total area of , of which is land and is water (0.27%). As per the USGS National Elevation Dataset, the elevation is .