Lupus is a city in Moniteau County, Missouri, United States. The population was 28 at the 2020 census. It is part of the Jefferson City …Lupus is a city in Moniteau County, Missouri, United States. The population was 28 at the 2020 census. It is part of the Jefferson City metropolitan area. A post office called Lupus was established in 1884, and remained in operation until 1955. Lupus is a name derived from Latin meaning "wolf".