Howell, MissouriHowell is an unincorporated community in St. Charles County, in the U.S. state of Missouri. Much of the community has been annexed by St. Peters.HistoryA post office called Howell was established in 1900, and remained in operation until 1917. The community has the name of Francis Howell, a local educator. Jazz pianists Ralph Sutton and Barbara Sutton Curtis were from Howell.