Where is Area Code 636?

Max of Missouri with area code 636 highlighted

Area code 636 is found in the US state of Missouri. Primarily servicing the city of Saint Charles (population: 137739), area code 636 covers 9 counties of Missouri.

Located in the Central time zone, area code 636 is on the same time as Chicago, IL.

Area code 636 was brought into effect on May 22, 1999. 636 was split from the parent 314 area code.

Counties in Area Code 636

  • Franklin,
  • Jefferson,
  • Lincoln,
  • Montgomery,
  • Saint Charles,
  • Saint Louis,
  • Warren,
  • Washington.

Most Populous Cities in Area Code 636

City County City Population
Saint Charles Saint Charles 137,739
Ballwin Saint Louis 92,744
O Fallon Saint Charles 91,566
Saint Peters Saint Charles 72,435
Chesterfield Saint Louis 59,310
Fenton Saint Louis 44,295
Wentzville Saint Charles 36,561
Arnold Jefferson 35,678
Imperial Jefferson 26,609
Festus Jefferson 26,572
Troy Lincoln 23,698
Washington Franklin 21,507
De Soto Jefferson 20,853
Lake Saint Louis Saint Charles 19,874
Union Franklin 17,400
High Ridge Jefferson 16,002
Warrenton Warren 15,887
Hillsboro Jefferson 15,822
Pacific Franklin 15,657
House Springs Jefferson 14,592
Eureka Saint Louis 13,888
Saint Clair Franklin 11,788
Barnhart Jefferson 10,040
Wright City Warren 9,839
Grover Saint Louis 8,524

Note: The above list is based off of the top 25 most populous cities in the area code as per 2012 United States Census Bureau estimates.

View all United States Area Codes.