| Index | St. Marys | Kansas | National |
| Average Test Scores | 36% | 35% | 48% |
| Student/Teacher ratio | 12:1 | 14:1 | 16:1 |
| Total public schools | 2 | 970 | 79,221 |
| Total private schools | n/a | 190 | 24,874 |
| Total post-secondary schools | n/a | 86 | 7,963 |

| Index | St. Marys | Kansas | National |
| Completed 8th grade | 92.3% | 87.4% | 84.3% |
| Completed high school | 91.6% | 86.1% | 83.0% |
| Completed some college | 64.4% | 63.7% | 59.4% |
| Completed associate degree | 30.2% | 39.8% | 38.5% |
| Completed bachelors | 22.0% | 31.6% | 30.3% |
| Completed masters | 10.3% | 11.4% | 11.5% |
| Completed professional degree | 4.9% | 3.0% | 3.3% |
| Completed doctorate | 1.5% | 1.2% | 1.3% |
There are a total of 2 public schools, n/a private schools and n/a post-secondary schools in St. Marys. Using the proficiency score averages, the average test scores for St. Marys, KS schools is 36%. The average student to teacher ratio is 12:1. In St. Marys, KS, an average of 92.3% of students have completed 8th grade and an average of 91.6% have completed high school.
| City | Population | Avg. Test Scores | National Avg. |
| Maple Hill, KS | 621 | 70% | 45.8% |
| Alma, KS | 940 | 53% | 9.4% |
| Silver Lake, KS | 1,491 | 50% | 4.7% |
| Wamego, KS | 4,642 | 36% | 24.7% |
| Paxico, KS | 244 | 33% | 30.7% |
| St. Marys, KS | 2,824 | 36% | 25.5% |
| City | Population | Avg. Test Scores | National Avg. |
| Tusculum, TN | 2,824 | 38% | 21.9% |
| St. Henry, OH | 2,825 | 85% | 77.8% |
| Riverdale, CA | 2,825 | 41% | 14.8% |
| Louisville, GA | 2,825 | 20% | 58.0% |
| Quarryville, PA | 2,826 | 52% | 7.7% |
| St. Marys, KS | 2,824 | 36% | 25.5% |