Founded in 1683, Suffolk County is one of 62 counties in the state of New York. Historically, Suffolk County was one of 12 original counties created in the New York colony. The city of Riverhead is the county seat. With FIPS code of 103, Suffolk County has a population of 1,526,344 and area of 2,373 square miles (6,146 km2).
List of all cities in Suffolk County, NY alphabetically
| City/Town | Postal Code | Area Code |
| Abmps, NY | 11750 | 631 |
| Amagansett, NY | 11930 | 631 |
| Amity Harbor, NY | 11701 | 631 |
| Amityville, NY | 11701 | 631 |
| 11708 | 631 | |
| Aquebogue, NY | 11931 | 631 |
| Asharoken, NY | 11768 | 631 |
| Babylon, NY | 11702 | 631 |
| 11703 | 631 | |
| 11704 | 631 | |
| 11707 | 631 | |
| Baiting Hollow, NY | 11933 | 631 |
| Bay Hills, NY | 11743 | 631 |
| Bay Point, NY | 11963 | 631 |
| Bay Port, NY | 11705 | 631 |
| Bay Shore, NY | 11706 | 631 |
| Bayberry Point, NY | 11751 | 631 |
| Baycrest, NY | 11743 | 631 |
| Bayport, NY | 11705 | 631 |
| Bayshore, NY | 11706 | 631 |
| Beach Hampton, NY | 11930 | 631 |
| Beech Croft, NY | 11743 | 631 |
| Belle Terre, NY | 11777 | 631 |
| Bellport, NY | 11713 | 631 |
| Blue Point, NY | 11715 | 631 |
| Bohemia, NY | 11716 | 631 |
| Box Hill, NY | 11780 | 631 |
| Brentwood, NY | 11717 | 631 |
| Bridge Hampton, NY | 11932 | 631 |
| Brightwaters, NY | 11718 | 631 |
| Brookhaven, NY | 11719 | 631 |
| Calverton, NY | 11933 | 631 |
| Canaan Lake, NY | 11772 | 631 |
| Captree Island, NY | 11702 | 631 |
| Carver Park, NY | 11980 | 631 |
| Center Moriches, NY | 11934 | 631 |
| Center Port, NY | 11721 | 631 |
| Centereach, NY | 11720 | 631 |
| Centerport, NY | 11721 | 631 |
| Central Islip, NY | 11722 | 631 |
| 11749 | 631 | |
| 11760 | 631 | |
| Cherry Grove, NY | 11782 | 631 |
| Cold Spring Harbor, NY | 11724 | 631 |
| Cold Spring Hills, NY | 11743 | 631 |
| Commack, NY | 11725 | 631 |
| Copiague, NY | 11726 | 631 |
| Coram, NY | 11727 | 631 |
| Corneil Estates, NY | 11770 | 631 |
| Crab Meadow, NY | 11768 | 631 |
| CTR Moriches, NY | 11934 | 631 |
| Cutchogue, NY | 11935 | 631 |
| Davis Park, NY | 11772 | 631 |
| Deer Park, NY | 11729 | 631 |
| Deer Wells, NY | 11780 | 631 |
| Deerpark, NY | 11729 | 631 |
| Dix Hills, NY | 11746 | 631 |
| 11747 | 631 | |
| Don Jagoda Assc Inc, NY | 11775 | 631 |
| East Hampton, NY | 11937 | 631 |
| East Islip, NY | 11730 | 631 |
| East Marion, NY | 11939 | 631 |
| East Moriches, NY | 11940 | 631 |
| East Northport, NY | 11731 | 631 |
| East Patchogue, NY | 11772 | 631 |
| East Quogue, NY | 11942 | 631 |
| East Setauket, NY | 11733 | 631 |
| East Yaphank, NY | 11967 | 631 |
| Eastport, NY | 11941 | 631 |
| Eatons Neck, NY | 11768 | 631 |
| Edgewood, NY | 11717 | 631 |
| Elwood, NY | 11731 | 631 |
| Fair Harbor, NY | 11706 | 631 |
| Farmingville, NY | 11738 | 631 |
| Fire Island, NY | 11770 | 631 |
| Fire Island Pines, NY | 11782 | 631 |
| Fishers Island, NY | 06390 | 631 |
| Flanders, NY | 11901 | 631 |
| Flowerfield, NY | 11780 | 631 |
| Fort Salonga, NY | 11768 | 631 |
| Gilgo Beach, NY | 11702 | 631 |
| Gordon Heights, NY | 11763 | 631 |
| Great River, NY | 11739 | 631 |
| Greenlawn, NY | 11740 | 631 |
| Greenport, NY | 11944 | 631 |
| Halesite, NY | 11743 | 631 |
| Hampton Bays, NY | 11946 | 631 |
| Harbor Heights, NY | 11743 | 631 |
| Hauppauge, NY | 11749 | 631 |
| 11788 | 631 | |
| Head of the Harbor, NY | 11780 | 631 |
| 11790 | 631 | |
| Heer Park, NY | 11757 | 631 |
| Hither Plns, NY | 11954 | 631 |
| Holbrook, NY | 11741 | 631 |
| Holtsville, NY | 00501 | 631 |
| 00544 | 631 | |
| 11742 | 631 | |
| Hunt, NY | 11743 | 631 |
| Huntingtn Station, NY | 11746 | 631 |
| 11747 | 631 | |
| 11750 | 631 | |
| Huntington, NY | 11743 | 631 |
| Huntington Bay, NY | 11743 | 631 |
| Huntington Station, NY | 11746 | 631 |
| 11747 | 631 | |
| 11750 | 631 | |
| I R S Service Center, NY | 00501 | 631 |
| IRS Service Center, NY | 00544 | 631 |
| Islandia, NY | 11749 | 631 |
| 11760 | 631 | |
| Islip, NY | 11751 | 631 |
| Islip Manor, NY | 11751 | 631 |
| Islip Terrace, NY | 11752 | 631 |
| Jamesport, NY | 11947 | 631 |
| Kings Park, NY | 11754 | 631 |
| Kismet, NY | 11706 | 631 |
| Knollwood Beach, NY | 11743 | 631 |
| Lake Grove, NY | 11755 | 631 |
| Lake Panamoka, NY | 11961 | 631 |
| Lake Ronkonkoma, NY | 11779 | 631 |
| Lake Ronkonkoma Heights, NY | 11779 | 631 |
| Laurel, NY | 11948 | 631 |
| Lindenhurst, NY | 11757 | 631 |
| Lloyd Harbor, NY | 11743 | 631 |
| Lloyd Neck, NY | 11743 | 631 |
| Manor Park, NY | 11950 | 631 |
| Manorville, NY | 11949 | 631 |
| Marconiville, NY | 11726 | 631 |
| Mastic, NY | 11950 | 631 |
| Mastic Beach, NY | 11951 | 631 |
| Mattituck, NY | 11952 | 631 |
| Medford, NY | 11763 | 631 |
| Melville, NY | 11747 | 631 |
| 11750 | 631 | |
| 11775 | 631 | |
| Middle Island, NY | 11953 | 631 |
| Miller Place, NY | 11764 | 631 |
| Montauk, NY | 11954 | 631 |
| Moriches, NY | 11955 | 631 |
| Mount Sinai, NY | 11766 | 631 |
| Nassau Point, NY | 11935 | 631 |
| Nesconset, NY | 11767 | 631 |
| New Suffolk, NY | 11956 | 631 |
| Nissequogue, NY | 11780 | 631 |
| North Amityville, NY | 11701 | 631 |
| North Babylon, NY | 11703 | 631 |
| North Bay Shore, NY | 11706 | 631 |
| North Bellport, NY | 11713 | 631 |
| North Haven, NY | 11963 | 631 |
| North Lindenhurst, NY | 11757 | 631 |
| North Patchogue, NY | 11772 | 631 |
| Northampton, NY | 11901 | 631 |
| Northport, NY | 11768 | 631 |
| Oak Beach, NY | 11702 | 631 |
| Oak Island, NY | 11702 | 631 |
| Oakdale, NY | 11769 | 631 |
| Ocean Bay Park, NY | 11770 | 631 |
| Ocean Beach, NY | 11770 | 631 |
| Old Field, NY | 11733 | 631 |
| Old Mastic, NY | 11951 | 631 |
| Old Westfield, NY | 11784 | 631 |
| Orient, NY | 11957 | 631 |
| Orient Point, NY | 11957 | 631 |
| P J S, NY | 11776 | 631 |
| 11777 | 631 | |
| Panamoka, NY | 11961 | 631 |
| Patchogue, NY | 11772 | 631 |
| Peconic, NY | 11958 | 631 |
| Pine Air, NY | 11717 | 631 |
| Pine Neck, NY | 11963 | 631 |
| Pjs, NY | 11776 | 631 |
| Pjs, NY | 11777 | 631 |
| Point Jefferson Station, NY | 11777 | 631 |
| Point O Woods, NY | 11706 | 631 |
| Poquott, NY | 11733 | 631 |
| Port Jefferson, NY | 11777 | 631 |
| Port Jefferson Station, NY | 11776 | 631 |
| 11777 | 631 | |
| Promised Land, NY | 11930 | 631 |
| Quioque, NY | 11978 | 631 |
| Quogue, NY | 11959 | 631 |
| Remsenburg, NY | 11960 | 631 |
| Ridge, NY | 11961 | 631 |
| Riverhead, NY | 11901 | 631 |
| Rivers Edge, NY | 11950 | 631 |
| Rocky Point, NY | 11778 | 631 |
| Ronkonkoma, NY | 11749 | 631 |
| 11779 | 631 | |
| Sag Harbor, NY | 11963 | 631 |
| Sagaponack, NY | 11962 | 631 |
| Saint James, NY | 11780 | 631 |
| Saltaire, NY | 11706 | 631 |
| San Remo, NY | 11754 | 631 |
| Sayville, NY | 11782 | 631 |
| Scotts Beach, NY | 11789 | 631 |
| Seaview, NY | 11770 | 631 |
| Selden, NY | 11784 | 631 |
| Setauket, NY | 11733 | 631 |
| Shelter Island, NY | 11964 | 631 |
| Shelter Island Heights, NY | 11965 | 631 |
| Shirley, NY | 11967 | 631 |
| Shoreham, NY | 11786 | 631 |
| Smiths Point, NY | 11967 | 631 |
| Smithtown, NY | 11787 | 631 |
| Smithtown, NY | 11788 | 631 |
| So Huntington, NY | 11746 | 631 |
| Sound Beach, NY | 11789 | 631 |
| South Hampton, NY | 11968 | 631 |
| 11969 | 631 | |
| South Hauppauge, NY | 11722 | 631 |
| South Haven, NY | 11719 | 631 |
| South Huntington, NY | 11746 | 631 |
| South Jamesport, NY | 11970 | 631 |
| South Setauket, NY | 11720 | 631 |
| Southampton, NY | 11968 | 631 |
| 11969 | 631 | |
| Southold, NY | 11971 | 631 |
| Speonk, NY | 11972 | 631 |
| Stony Brook, NY | 11790 | 631 |
| 11794 | 631 | |
| Strongs Neck, NY | 11733 | 631 |
| Sunken Meadow, NY | 11768 | 631 |
| Suny Stony Brook, NY | 11794 | 631 |
| Terryville, NY | 11776 | 631 |
| Upton, NY | 11973 | 631 |
| Wading River, NY | 11792 | 631 |
| Wainscott, NY | 11975 | 631 |
| Water Mill, NY | 11976 | 631 |
| Watermill, NY | 11976 | 631 |
| West Babylon, NY | 11704 | 631 |
| 11707 | 631 | |
| West Bay Shore, NY | 11706 | 631 |
| West Brentwood, NY | 11717 | 631 |
| West Gilgo Beach, NY | 11702 | 631 |
| West Hampton, NY | 11977 | 631 |
| West Hampton Beach, NY | 11978 | 631 |
| West Hills, NY | 11743 | 631 |
| West Islip, NY | 11795 | 631 |
| West Sayville, NY | 11796 | 631 |
| Westhampton, NY | 11977 | 631 |
| Westhampton Beach, NY | 11978 | 631 |
| Westhampton Dunes, NY | 11978 | 631 |
| Wheatley Heights, NY | 11798 | 631 |
| Wildwood, NY | 11792 | 631 |
| Willwood, NY | 11792 | 631 |
| Wincoma, NY | 11743 | 631 |
| Wtr Mill, NY | 11976 | 631 |
| Wyandanch, NY | 11798 | 631 |
| Yaphank, NY | 11980 | 631 |