Imperial is a census-designated place (CDP) in Jefferson County, Missouri, United States, and is a suburb of St. Louis.

Imperial is located in northeastern Jefferson County and is bordered to the north by Arnold, to the south by Barnhart, and to the east by the Mississippi River, which forms the Illinois state line.

Interstate 55 runs through Imperial, with access from Exits 185 (Secondary Route M) and 186 (Main Street).

Mastodon State Historic Site is located in Imperial.

21.3% of all households were made up of individuals, and 6.9% had someone living alone who was 65 years of age or older.

20.3% of all households were made up of individuals, and 6.7% had someone living alone who was 65 years of age or older.

A small portion of the CDP and several surrounding areas with Imperial addresses are zoned to the Fox C-6 School District.

Fox C-6 operates Seckman High School outside of the CDP.