For the 2026 school year, there are 9 public charter schools serving 2,517 students in King County, WA. The top-ranked public charter schools in King County, WA are Impact Public Schools, Rainier Prep and Summit Public School Atlas. Overall testing rank is based on a school's combined math and reading proficiency test score ranking.
King County, WA public charter schools have an average math proficiency score of 41% (versus the Washington public charter school average of 41%), and reading proficiency score of 51% (versus the 54% statewide average). Charter schools in King County have an average ranking of 6/10, which is in the top 50% of Washington public charter schools.
Minority enrollment is 83% of the student body (majority Black), which is more than the Washington public charter school average of 65% (majority Black and Hispanic).
Best Public Charter Schools in King County (2026)
School
(Math and Reading Proficiency)
(Math and Reading Proficiency)
Location
Quick Facts
Rank: #11.
Impact Public Schools
Charter School
(Math: 52% | Reading: 55-59%)
Rank:
Rank:
8/
Top 30%10
3438 S. 148th Street
Seattle, WA 98168
(206) 712-7640
Seattle, WA 98168
(206) 712-7640
Gr: K-5 | 505 students Student-teacher ratio: 16:1 Minority enrollment: 90%
Rank: #22.
Rainier Prep
Charter School
(Math: 50% | Reading: 51%)
Rank:
Rank:
7/
Top 50%10
10211 12th Ave S
Seattle, WA 98168
(206) 494-5979
Seattle, WA 98168
(206) 494-5979
Gr: 5-8 | 359 students Student-teacher ratio: 14:1 Minority enrollment: 95%
Rank: #33.
Summit Public School Atlas
Charter School
(Math: 43% | Reading: 52%)
Rank:
Rank:
6/
Top 50%10
9601 35th Avenue Sw
Seattle, WA 98126
(206) 307-7645
Seattle, WA 98126
(206) 307-7645
Gr: 6-12 | 566 students Student-teacher ratio: 17:1 Minority enrollment: 63%
Rank: #44.
Summit Public School Sierra
Charter School
(Math: 25-29% | Reading: 60-64%)
Rank:
Rank:
6/
Top 50%10
1025 S King St
Seattle, WA 98134
(206) 453-2520
Seattle, WA 98134
(206) 453-2520
Gr: 9-12 | 214 students Student-teacher ratio: 15:1 Minority enrollment: 58%
Rank: #55.
Summit Public School Olympus
Charter School
(Math: 11-19% | Reading: 50-59%)
Rank:
Rank:
3/
Bottom 50%10
409 Puyallup Ave
Seattle, WA 98134
(253) 444-9781
Seattle, WA 98134
(253) 444-9781
Gr: 9-12 | 110 students Student-teacher ratio: 10:1 Minority enrollment: 87%
Rank: #66.
Rainier Valley Leadership Academy
Charter School
(Math: 10-14% | Reading: 25-29%)
Rank:
Rank:
1/
Bottom 50%10
6020 Rainier Avenue S
Seattle, WA 98118
(206) 659-0956
Seattle, WA 98118
(206) 659-0956
Gr: 6-12 | 121 students Student-teacher ratio: 9:1 Minority enrollment: 99%
Rank: n/an/a
Cascade Public Schools
Magnet School
Charter School
Charter School
22419 Pacific Highway South
Seattle, WA 98198
(253) 271-8629
Seattle, WA 98198
(253) 271-8629
Gr: 9-12 | 126 students Student-teacher ratio: 16:1 Minority enrollment: 90%
Rank: n/an/a
Impact Black River Elementary School
Charter School
16950 116th Ave Se
Renton, WA 98058
(206) 712-7640
Renton, WA 98058
(206) 712-7640
Gr: K-5 | 209 students Student-teacher ratio: 16:1 Minority enrollment: 88%
Rank: n/an/a
Impact Salish Sea Elementary School
Charter School
3900 Holly Park Dr South
Seattle, WA 98118
(206) 712-7640
Seattle, WA 98118
(206) 712-7640
Gr: K-5 | 385 students Student-teacher ratio: 15:1 Minority enrollment: 93%
Frequently Asked Questions
What are the top-ranked public charter schools in King County, WA?
The top-ranked public charter schools in King County, WA include Impact Public Schools, Rainier Prep and Summit Public School Atlas. King County has one of the highest concentrations of top-ranked public schools in Washington.
How many public charter schools are located in King County?
9 public charter schools are located in King County.
What is the racial composition of students in King County?
King County public charter schools minority enrollment is 83% of the student body (majority Black), which is more than the Washington public charter schools average of 65% (majority Black and Hispanic).
Which public charter schools in King County are often viewed compared to one another?
Popular comparisons of public charter schools in King County include: Summit Public School Olympus vs. Summit Public School Atlas, Summit Public School Sierra vs. Summit Public School Atlas, Summit Public School Olympus vs. Summit Public School Sierra
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