Tripoli is a city in Bremer County, Iowa, United States. The population was 1,191 at the time of the 2020 census. It is part of the Waterloo–Ceda…Tripoli is a city in Bremer County, Iowa, United States. The population was 1,191 at the time of the 2020 census. It is part of the Waterloo–Cedar Falls Metropolitan Statistical Area. The Tripoli Post Office opened in 1860.