Isanti is a city in Isanti County, Minnesota, United States. The population was 6,804 at the 2020 census. The name Isanti is composed of two …Isanti is a city in Isanti County, Minnesota, United States. The population was 6,804 at the 2020 census. The name Isanti is composed of two Dakota words: isan and ati, and refers to the Santee Dakota people.