Area Code 314 January 18, 2021 allcitycodes Telephone Codes 0 Where is area code 314 located? Below you will find a list of all cities covered by area code 314 in Missouri. Bridgeton, MO Earth City, MO Glencoe, MO Hazelwood, MO Maryland Heights, MO Saint Ann, MO Valley Park, MO Related Posts Australia Area Code Netherlands Area Code Vermont Area Codes Luxembourg Area Code Andorra Area Code Area Code 218 Micronesia Area Code Area Code 775