Bettendorf is a city in Scott County, Iowa, United States. It is the 15th largest city of Iowa and the third-largest city in the "Quad Cities". It is part of the Davenport–Moline–Rock Island, IA-IL Metropolitan Statistical Area. The population was 39,102 at the 2020 census. Bettendorf is one of the Quad Cities, along with neighboring Davenport and the Illinois cities of Moline, East Moline and Rock Island. The Quad Cities were population 379,374 at the 2022 estimate.