Sapulpa is a city in Creek and Tulsa counties in the U.S. state of Oklahoma. The population was 21,929 at the time of the 2020 censu…Sapulpa is a city in Creek and Tulsa counties in the U.S. state of Oklahoma. The population was 21,929 at the time of the 2020 census, compared with 20,544 at the 2010 census. It is the county seat of Creek County.