Area Code 636 at a Glance
| Area code | 636 |
| Region | Missouri |
| Country | United States |
| Primary timezone | America/Chicago |
| Dialing format | +1 (636) NXX-XXXX |
Cities and Places Using Area Code 636
Based on prefix-level carrier data, area code 636 covers places including:
- St. Charles, MO
- O'Fallon, MO
- Fenton, MO
- Chesterfield, MO
- St. Peters, MO
- Wentzville, MO
- Festus, MO
- Arnold, MO
- Ballwin, MO
- Eureka, MO
- Union, MO
- Washington, MO
Frequently Asked Questions
Where is area code 636?
Area code 636 serves Missouri, United States.
Who is calling me from area code 636?
A call from area code 636 most likely originates from Missouri, but caller ID can be spoofed. If an unknown caller asks for personal or payment information, hang up and call the organization back on its official number.
How do I dial a 636 number?
Within North America: dial 1-636 followed by the 7-digit number. From abroad: your international prefix (like 00 or +), then 1 636 and the number.