Centreville Layton School Photo - Beautiful campus

Best Delaware Private High Schools Belonging to National Association of Independent Schools (NAIS) (2025-26)

For the 2025-26 school year, there are 8 private high schools belonging to National Association of Independent Schools (NAIS) serving 4,336 students in Delaware. You can also find more schools membership associations in Delaware.
The top ranked private high schools belonging to National Association of Independent Schools (NAIS) in Delaware include Archmere Academy, Tower Hill School, and The Tatnall School.
The average acceptance rate is 84%, which is lower than the Delaware private high school average acceptance rate of 87%.
50% of private high schools belonging to National Association of Independent Schools (NAIS) in Delaware are religiously affiliated (most commonly Catholic and Friends).

Top Ranked Private High Schools Belonging to National Association of Independent Schools (NAIS) in Delaware (2025-26)

School
Location
Quick Facts
Centreville Layton School
Centreville Layton School Photo - Beautiful campus
Alternative School
6201 Kennett Pike
Wilmington, DE 19807
(302) 571-0230
Gr: K-12 | 83 students Avg. class size: 8 students Sports: 6 Tuition & acceptance rate listed
Wilmington Friends School
Wilmington Friends School Photo - Quaker education teaches students that they share in the obligation to answer what is best in themselves and in others--developing talents to the fullest, and respecting the strengths, efforts, and perspectives of all.
(Friends)
(1)
101 School Road
Wilmington, DE 19803
(302) 576-2900
Gr: NS-12 | 690 students Avg. class size: 12 students Sports: 14 | Extracurrculars: 39 Tuition listed
Archmere Academy
Archmere Academy Photo
(Catholic)
(7)
3600 Philadelphia Pike
Claymont, DE 19703
(302) 798-6632
Gr: 9-12 | 501 students Avg. class size: 15 students Sports: 20 | Extracurrculars: 38 Tuition listed
St. Andrew's School
(Episcopal)
350 Noxontown Rd
Middletown, DE 19709
(302) 285-4231
Gr: 9-12 | 315 students Sports: 15 Tuition listed
Saint Mark's High School
Saint Mark's High School Photo
(Catholic)
(10)
2501 Pike Creek Road
Wilmington, DE 19808
(302) 757-8721
Gr: 9-12 | 716 students Avg. class size: 20 students Sports: 17 | Extracurrculars: 34 Tuition listed
Sanford School
Sanford School Photo
(2)
6900 Lancaster Pike
Hockessin, DE 19707
(302) 235-6503
Gr: NS-12 | 685 students Avg. class size: 13 students Sports: 14 | Extracurrculars: 9 Tuition & acceptance rate listed
The Tatnall School
The Tatnall School Photo - Tatnall's 110-acre campus is located just west of Wilmington in Greenville, Delaware. Housing a National Wildlife Federation-accredited schoolyard habitat, five outdoor classrooms and bordering the Downs Nature Conservancy, the spacious campus provides expansive playing fields and opportunities for outdoor environmental study.
(13)
1501 Barley Mill Road
Wilmington, DE 19807
(302) 892-4296
Gr: NS-12 | 486 students Avg. class size: 12 students Sports: 15 | Extracurrculars: 9 Tuition listed
Tower Hill School
Tower Hill School Photo - Tower Hill School resides on a 44-acre campus with state-of- the-art athletic facilities and impressive academic and arts areas.
2813 W 17th Street
Wilmington, DE 19806
(302) 575-0550
Gr: NS-12 | 860 students Avg. class size: 15 students Sports: 16 | Extracurrculars: 24 Tuition & acceptance rate listed

Recent Articles

Transferring from Public to Private School Mid-Year: What to Expect
Transferring from Public to Private School Mid-Year: What to Expect
Considering a mid-year transfer from public to private school? Learn what to expect with admissions, academic placement, social adjustment, and financial aid to ensure a smooth transition.
A Guide to Day vs. Boarding School: Which Is Right for Your Family
A Guide to Day vs. Boarding School: Which Is Right for Your Family
Discover the key differences between day and boarding schools to determine the best fit for your child. Explore benefits, costs, lifestyle factors, and questions to help guide your family’s decision.
The A to Z of Private Schools 2025
The A to Z of Private Schools 2025
Explore the A to Z of private schools in 2025—from admissions to tuition—offering parents and educators clear insights into today’s options.