Decatur is the name of several places in the United States. Most, if not all, are named for Stephen Decatur, U.S. naval officer, known for his exploits at Tripoli against the Barbary Pirates and the toast "My country, right or wrong".
- Decatur, Alabama
- Decatur, Arkansas
- Decatur, Georgia
- Decatur, Illinois
- Decatur, Indiana
- Decatur, Michigan
- Decatur, Mississippi
- Decatur, Nebraska
- Decatur, Tennessee
- Decatur, Texas
- Decatur County, Indiana
- Decatur County, Iowa
- Decatur County, Kansas
- Decatur County, Tennessee
- Decatur Township, Pennsylvania