Educational levels
Data about Long Island from the Census Bureau's 2008-2010 American Community Survey for the county and town level on educational attainment. Some towns are not listed because the number of residents surveyed was too small. Also, because this information is based on surveys, there is a different margin of error for each statistic. A complete listing of those margins and of all the data from Long Island, including information from 45 communities with populations of 20,000 or more, is available on this PDF.
| Location | Population over 25 | Less than grade 9 | HS no diploma | HS diploma | Some college no degree | Associates degree | Bachelors degree | Post grad degree | HS graduate or higher | Bachelors or higher |
| Glen Cove City | 18,512 | 10.4 | 5.5 | 27.0 | 15.8 | 3.0 | 21.4 | 16.8 | 84.0 | 38.2 |
| Southold Town | 17,016 | 7.0 | 3.6 | 26.7 | 18.4 | 7.2 | 22.4 | 14.7 | 89.4 | 37.1 |
| Islip Town | 220,898 | 6.8 | 7.1 | 32.4 | 18.7 | 9.2 | 14.9 | 10.9 | 86.1 | 25.8 |
| Hempstead Town | 507,374 | 6.0 | 6.0 | 26.3 | 16.9 | 8.2 | 20.5 | 16.0 | 88.0 | 36.6 |
| Southampton Town | 41,776 | 5.8 | 5.5 | 23.2 | 16.5 | 7.7 | 23.2 | 18.1 | 88.7 | 41.3 |
| Nassau County | 908,978 | 5.2 | 5.1 | 25.2 | 15.9 | 7.6 | 22.6 | 18.4 | 89.7 | 41.0 |
| Babylon Town | 142,458 | 5.2 | 7.3 | 35.7 | 19.4 | 9.1 | 14.5 | 8.8 | 87.5 | 23.3 |
| North Hempstead Town | 154,232 | 5.2 | 4.3 | 20.6 | 12.9 | 5.6 | 26.6 | 24.8 | 90.5 | 51.4 |
| Long Beach City | 25,835 | 4.5 | 3.8 | 24.9 | 15.2 | 7.4 | 24.4 | 19.7 | 91.6 | 44.1 |
| Suffolk County | 999,495 | 4.2 | 5.9 | 30.4 | 18.2 | 9.0 | 18.0 | 14.3 | 89.8 | 32.2 |
| Huntington Town | 139,124 | 3.7 | 4.0 | 21.6 | 14.9 | 8.7 | 25.8 | 21.2 | 92.3 | 47.0 |
| Riverhead Town | 22,952 | 3.7 | 5.6 | 31.9 | 20.8 | 8.0 | 13.8 | 16.2 | 90.7 | 30.0 |
| Brookhaven Town | 317,700 | 2.7 | 6.3 | 33.1 | 19.0 | 9.3 | 16.0 | 13.6 | 91.0 | 29.6 |
| Oyster Bay Town | 203,025 | 2.6 | 3.6 | 25.6 | 16.0 | 8.1 | 24.6 | 19.4 | 93.8 | 44.0 |
| East Hampton Town | 16,840 | 2.5 | 5.3 | 22.2 | 18.5 | 5.9 | 23.9 | 21.7 | 92.1 | 45.6 |
| Smithtown Town | 78,687 | 1.7 | 2.4 | 26.3 | 17.7 | 9.5 | 22.9 | 19.4 | 95.9 | 42.3 |