| Index | Holtsville | New York | National |
| Average Test Scores | 46% | 56% | 48% |
| Student/Teacher ratio | n/a | n/a | 16:1 |
| Total public schools | 4 | 4,060 | 79,221 |
| Total private schools | n/a | 1,092 | 24,874 |
| Total post-secondary schools | n/a | 483 | 7,963 |


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| Index | Holtsville | New York | National |
| Completed 8th grade | 90.1% | 83.5% | 84.3% |
| Completed high school | 89.8% | 82.1% | 83.0% |
| Completed some college | 63.0% | 59.5% | 59.4% |
| Completed associate degree | 40.0% | 43.4% | 38.5% |
| Completed bachelors | 29.8% | 34.7% | 30.3% |
| Completed masters | 12.3% | 15.1% | 11.5% |
| Completed professional degree | 2.2% | 4.2% | 3.3% |
| Completed doctorate | 1.1% | 1.5% | 1.3% |
There are a total of 4 public schools, n/a private schools and n/a post-secondary schools in Holtsville. Using the proficiency score averages, the average test scores for Holtsville, NY schools is 46%. The average student to teacher ratio is n/a. In Holtsville, NY, an average of 90.1% of students have completed 8th grade and an average of 89.8% have completed high school.
| City | Population | Avg. Test Scores | National Avg. |
| Shoreham, NY | 375 | 82% | 69.8% |
| West Sayville, NY | 4,956 | 82% | 69.8% |
| Hauppauge, NY | 19,661 | 80% | 66.3% |
| Setauket-East Setauket, NY | 14,174 | 80% | 65.6% |
| Port Jefferson, NY | 8,016 | 77% | 60.8% |
| Holtsville, NY | 18,574 | 46% | 3.6% |
| City | Population | Avg. Test Scores | National Avg. |
| Winthrop Town, MA | 18,558 | 58% | 20.5% |
| Lake Ronkonkoma, NY | 18,555 | 65% | 34.4% |
| Brownwood, TX | 18,554 | 32% | 33.9% |
| Rancho Mirage, CA | 18,537 | 44% | 7.8% |
| Altus, OK | 18,533 | 42% | 13.3% |
| Holtsville, NY | 18,574 | 46% | 3.6% |