La Monte is a city in Pettis County, Missouri, United States.

La Monte was originally called Boomer, and under the latter name was platted in 1866.

[4] The present name of La Monte, after an acquaintance of an early postmaster, was adopted in 1870 when the railroad was extended through the neighborhood.

Knob Noster is six miles west in adjacent Johnson County.

27.1% of all households were made up of individuals, and 13.3% had someone living alone who was 65 years of age or older.

26.3% of all households were made up of individuals, and 11.7% had someone living alone who was 65 years of age or older.