Arnold, Missouri

Arnold, Missouri
Arnold Water Tower from I-55 North
(color is sky blue since Nov 2015)
Interactive map of Arnold, Missouri
Coordinates: 38°25′47″N 90°22′24″W / 38.42972°N 90.37333°W / 38.42972; -90.37333
CountryUnited States
StateMissouri
CountyJefferson
Government
 • TypeMayor-Administrator-Council
 • MayorWilliam Moritz
 • AdministratorAnthony Traxler
Area
 • Total
11.53 sq mi (29.86 km2)
 • Land11.53 sq mi (29.85 km2)
 • Water0.0039 sq mi (0.01 km2)
Elevation
522 ft (159 m)
Population
 (2020)
 • Total
20,858
 • Density1,809.9/sq mi (698.79/km2)
Time zoneUTC-6 (Central (CST))
 • Summer (DST)UTC-5 (CDT)
ZIP code
63010
Area code636
FIPS code29-01972
GNIS ID2393991
Websitearnoldmo.org

Arnold is a city in northeastern Jefferson County, Missouri, situated near the confluence of the Meramec and Mississippi rivers. A suburb of St. Louis, the city lies within the Greater St. Louis metropolitan statistical area. The population was 20,858 at the 2020 United States census, which makes it the most populous community in the county.