District 31
- Alabama's 31st Senate district
- California's 31st State Assembly district
- California's 31st congressional district
- California's 31st senatorial district
- Colorado's 31st Senate district
- Connecticut's 31st House of Representatives district
- Connecticut's 31st State Senate district
- District 31 (TV series)
- Florida's 31st House of Representatives district
- Idaho's 31st legislative district
- Iowa's 31st House of Representatives district
- Iowa's 31st Senate district
- Kansas's 31st Senate district
- Kentucky's 31st Senate district
- Louisiana's 31st House of Representatives district
- Louisiana's 31st State Senate district
- Maryland Legislative District 31
- Massachusetts House of Representatives' 31st Middlesex district
- Michigan's 31st House of Representatives district
- Michigan's 31st Senate district
- Missouri's 31st Senate district
- New Jersey's 31st legislative district
- New York's 31st State Assembly district
- New York's 31st State Senate district
- New York's 31st congressional district
- North Carolina's 31st House district
- North Carolina's 31st Senate district
- Ohio's 31st senatorial district
- Oregon's 31st House district
- Pennsylvania House of Representatives, District 31
- Pennsylvania Senate, District 31
- Pennsylvania's 31st congressional district
- South Dakota's 31st legislative district
- Tennessee's 31st Senate district
- Texas Senate, District 31
- Texas's 31st House of Representatives district
- Texas's 31st congressional district
- United States House of Representatives
- Virginia's 31st House of Delegates district
- Virginia's 31st Senate district
- Washington's 31st legislative district
- Wisconsin's 31st Assembly district
- Wisconsin's 31st Senate district
- Wyoming's 31st House of Representatives district
- Wyoming's 31st State Senate district