Star is a city in northwestern Ada County, Idaho, with parts stretching into neighboring Canyon County. The population was 11,117 at the 2020 census, up from 5,793 in 2010. It was named in the 19th century by travelers on their way to Middleton and Boise who used the star on the school house to find east and west. The name stuck and it became Star, Idaho. Today, it is a rapidly growing suburb of Boise and its schools are shared with Middleton School District and West Ada School District.