New Bloomfield is a city in Cedar Township, Callaway County, Missouri, United States.

In 1827, a 'Round Prairie Post Office' was opened northwest of New Bloomfield, near what became Guthrie almost 50 years later, and near the southern border of a much larger historic Round Prairie Township (subdivided around 1890 to create what then became the northern portion of Guthrie Township).

[5][6] In 1836, a historic town of 'Bloomfield', next to or containing the Round Prairie Post Office, was first surveyed.

[5] In 1841, the Round Prairie Post Office was shut down and moved about 1/2 mile southward, clearly into Cedar Township, and was renamed 'New Bloomfield Post Office', around which today's town of New Bloomfield formed.

The Chicago & Alton Railroad went from the Missouri riverport at Cedar City, through Holts Summit, then New Bloomfield and Guthrie, then veered northeast toward Carrington, then Fulton, then McCredie, Auxvasse, and into Audrain County and the city of Mexico, and thereafter toward Illinois and Chicago to the east, or to Kansas City to the west.

Connection to St Louis was made via locations across the Mississippi River in Illinois until the MKT railroad was built in the 1890s.

26.2% of all households were made up of individuals, and 9.8% had someone living alone who was 65 years of age or older.

31.2% of all households were made up of individuals, and 16.0% had someone living alone who was 65 years of age or older.