Founded in 1643, Essex County is one of 14 counties in the state of Massachusetts. Historically, Essex County was one of four original counties created in the Massachusetts Bay Colony. Government abolished in 1999. The city of Salem, Lawrence is the county seat. With FIPS code of 9, Essex County has a population of 807,074 and area of 498 square miles (1,290 km2).
List of all cities in Essex County, MA alphabetically
| City/Town | Postal Code | Area Code |
| Amesbury, MA | 01913 | 978/351 |
| Andover, MA | 01810 | 978/351 |
| 01812 | 978/351 | |
| 01899 | 978/351 | |
| 05501 | 978/351 | |
| 05544 | 978/351 | |
| Bar Coded I R S, MA | 01899 | 978/351 |
| Beverly, MA | 01915 | 978/351 |
| Beverly Farms, MA | 01915 | 978/351 |
| Boxford, MA | 01921 | 978/351 |
| Bradford, MA | 01835 | 978/351 |
| Byfield, MA | 01922 | 978/351 |
| Danvers, MA | 01923 | 978/351 |
| East Lynn, MA | 01904 | 781/339 |
| Essex, MA | 01929 | 978/351 |
| General Elec Co, MA | 01910 | 781/339 |
| Georgetown, MA | 01833 | 978/351 |
| Gloucester, MA | 01930 | 978/351 |
| 01931 | 978/351 | |
| Groveland, MA | 01834 | 978/351 |
| Hamilton, MA | 01936 | 978/351 |
| 01982 | 978/351 | |
| Hathorne, MA | 01937 | 978/351 |
| Haverhill, MA | 01830 | 978/351 |
| 01831 | 978/351 | |
| 01832 | 978/351 | |
| 01833 | 978/351 | |
| 01835 | 978/351 | |
| Internal Revenue Service, MA | 01812 | 978/351 |
| Ipswich, MA | 01938 | 978/351 |
| IRS Service Center, MA | 05501 | 978/351 |
| IRS Service Center, MA | 05544 | 978/351 |
| Lawrence, MA | 01840 | 978/351 |
| 01841 | 978/351 | |
| 01842 | 978/351 | |
| 01843 | 978/351 | |
| Lynn, MA | 01901 | 781/339 |
| 01902 | 781/339 | |
| 01903 | 781/339 | |
| 01904 | 781/339 | |
| 01905 | 781/339 | |
| 01910 | 781/339 | |
| Lynnfield, MA | 01940 | 781/339 |
| Magnolia, MA | 01930 | 978/351 |
| Manchester, MA | 01944 | 978/351 |
| Manchester by the Sea, MA | 01944 | 978/351 |
| Marblehead, MA | 01945 | 781/339 |
| Merrimac, MA | 01860 | 978/351 |
| Methuen, MA | 01844 | 978/351 |
| Mhead, MA | 01945 | 781/339 |
| Middleton, MA | 01949 | 978/351 |
| Nahant, MA | 01908 | 781/339 |
| Newbury, MA | 01922 | 978/351 |
| 01951 | 978/351 | |
| Newburyport, MA | 01950 | 978/351 |
| 01951 | 978/351 | |
| North Andover, MA | 01845 | 978/351 |
| Peabody, MA | 01960 | 978/351 |
| Peabody, MA | 01961 | 978/351 |
| Pigeon Cove, MA | 01966 | 978/351 |
| Plum Island, MA | 01950 | 978/351 |
| 01951 | 978/351 | |
| Prides Crossing, MA | 01965 | 978/351 |
| Rockport, MA | 01966 | 978/351 |
| Rowley, MA | 01969 | 978/351 |
| Salem, MA | 01970 | 978/351 |
| 01971 | 978/351 | |
| Salisbury, MA | 01952 | 978/351 |
| Salisbury Beach, MA | 01952 | 978/351 |
| Saugus, MA | 01906 | 781/339 |
| South Hamilton, MA | 01982 | 978/351 |
| South Lawrence, MA | 01843 | 978/351 |
| South Lynnfield, MA | 01940 | 781/339 |
| Swampscott, MA | 01907 | 781/339 |
| Topsfield, MA | 01983 | 978/351 |
| Ward Hill, MA | 01835 | 978/351 |
| Wenham, MA | 01984 | 978/351 |
| West Boxford, MA | 01885 | 978/351 |
| West Lynn, MA | 01905 | 781/339 |
| West Newbury, MA | 01985 | 978/351 |
| West Peabody, MA | 01960 | 978/351 |