Wellington
- County:
- Sumner County
- County Seat:
- Yes
- Area (mi²):
- 7.618
- State:
- Kansas
Wellington is a city located in Sumner County, Kansas. Wellington has a 2026 population of 7,561. It is also the county seat of Sumner County. Wellington is currently declining at a rate of -0.54% annually and its population has decreased by -1.58% since the most recent census, which recorded a population of 7,682 in 2020.