| Index | Grenville | South Dakota | National |
| Average Test Scores | n/a | 48% | 48% |
| Student/Teacher ratio | n/a | 14:1 | 16:1 |
| Total public schools | n/a | 340 | 79,221 |
| Total private schools | n/a | 76 | 24,874 |
| Total post-secondary schools | n/a | 25 | 7,963 |

| Index | Grenville | South Dakota | National |
| Completed 8th grade | 91.0% | 89.1% | 84.3% |
| Completed high school | 73.1% | 86.8% | 83.0% |
| Completed some college | 44.9% | 60.4% | 59.4% |
| Completed associate degree | 34.6% | 38.5% | 38.5% |
| Completed bachelors | 29.5% | 27.5% | 30.3% |
| Completed masters | 15.4% | 8.1% | 11.5% |
| Completed professional degree | 15.4% | 2.5% | 3.3% |
| Completed doctorate | 0.0% | 1.2% | 1.3% |
There are a total of n/a public schools, n/a private schools and n/a post-secondary schools in Grenville. Using the proficiency score averages, the average test scores for Grenville, SD schools is n/a. The average student to teacher ratio is n/a. In Grenville, SD, an average of 91.0% of students have completed 8th grade and an average of 73.1% have completed high school.
| City | Population | Avg. Test Scores | National Avg. |
| Webster, SD | 1,728 | 65% | 34.7% |
| Waubay, SD | 550 | 36% | 24.5% |
| Agency Village, SD | 1,008 | 4% | 91.7% |
| Grenville, SD | 72 | n/a |
| City | Population | Avg. Test Scores | National Avg. |
| Bartlett, KS | 72 | 42% | 12.5% |
| Wikieup, AZ | 72 | 50% | 4.2% |
| Twin Hills, AK | 72 | 20% | 58.3% |
| Canaan, IN | 72 | 30% | 37.5% |
| Oak Hall, VA | 72 | 78% | 62.0% |
| Grenville, SD | 72 | n/a |