Total enrollment
3,993
-199 (-5%) vs SY 2020-21
6 schools in Mercer Island School District
Washington · 3,993 students · 1 city
Public-school families inside Mercer Island School District pick from 6 schools serving the district's roughly 3,993 K-12 students (4 elementary, 1 middle, and 1 high).
4-year change in Mercer Island School District
SY 2020-21 vs SY 2024-25School count
6
0 (0%) vs SY 2020-21
Source: NCES Common Core of Data, enrollment-weighted demographic averages
How Mercer Island School District ranks
Among districts| Measure | This district | In Washington | In the US |
|---|---|---|---|
| State test proficiency ranked highest first | 79.3% | #1 of 128 | N/A |
| Enrollment ranked largest first | 3,993 | #70 of 183 | #2,425 of 9,234 |
| Number of schools ranked most first | 6 | #106 of 183 | N/A |
| Students per teacher ranked fewest first | 18.0:1 | #94 of 183 | #7,720 of 9,044 |
| Free or reduced-price lunch share ranked highest first | 6.9% | #183 of 183 | #8,039 of 8,164 |
| Diversity index ranked most diverse first | 66.0% | #29 of 146 | #862 of 6,853 |
Districts need at least 2 schools and 500 students to be ranked. Test proficiency is ranked within the state only, since each state gives a different test. Each rank links to the full list.
Inside Mercer Island School District
State test results across the district's 6 scored schools run from Island Park Elementary at 88.0% proficient to Islander Middle School at 74.4%, a gap of 13.6 points. That is the 78th widest gap among 92 Washington districts with four or more scored schools.
Since 2017-18, the 6 district schools that reported both years went from 4,529 to 3,993 students (down 12%) and from 237 to 222 full-time teachers (down 6%), as of 2024-25.
Proficient is the average share of students meeting the state standard across each school's state tests in 2023-24 and 2024-25; schools with fewer than 100 students and schools serving specialized populations are left out. Staffing figures come from the NCES Common Core of Data and count only schools that reported students and teachers in both years.
| Name | City | Level | Grades | Enrollment |
|---|---|---|---|---|
| Mercer Island High School | Mercer Island | High | 09-12 | 1,439 |
| Islander Middle School | Mercer Island | Middle | 06-08 | 960 |
| West Mercer Elementary | Mercer Island | Elementary | KG-05 | 431 |
| Lakeridge Elementary School | Mercer Island | Elementary | KG-05 | 401 |
| Northwood Elementary School | Mercer Island | Elementary | PK-05 | 398 |
| Island Park Elementary | Mercer Island | Elementary | KG-05 | 364 |
About Mercer Island School District
Mercer Island School District operates 6 public schools across Washington, collectively enrolling roughly 3,993 students.
In terms of grade levels, Mercer Island School District comprises 4 elementary, 1 middle, and 1 high school.
Per-school enrollment averages around 666 in this district, meaningfully above the Washington typical of 446.
Trend over the past 4 years. Across the same 4-year window, public-school enrollment shrank 5%: 4,192 students in SY 2020-21 versus 3,993 in SY 2024-25.
On allk12, the community for Mercer Island School District discusses comparison threads between local schools and program reviews. Discussions cut across districts, schools, and grade levels.