Flat Creek Township is one of twenty-five townships in Barry County, Missouri, United States. As of the 2000 census, its population was 5,462.
Flat Creek was organized in 1844, taking its name from Flat Creek.
Flat Creek Township covers an area of and contains one incorporated settlement, Cassville (the county seat). It contains six cemeteries: Corinth, Horner, Oak Hill, Pilant, Quaker and Russell.
Flat Creek Township contains one airport or landing strip, Cassville Municipal Airport.