For the 2025-26 school year, there are 4 private high schools belonging to Independent Schools Association of the South West (ISAS) serving 3,652 students in Oklahoma. You can also find more schools membership associations in Oklahoma.
The top ranked private high schools belonging to Independent Schools Association of the South West (ISAS) in Oklahoma include Riverfield Country Day School, Casady School, and Holland Hall.
The average acceptance rate is 58%, which is lower than the Oklahoma private high school average acceptance rate of 79%.
50% of private high schools belonging to Independent Schools Association of the South West (ISAS) in Oklahoma are religiously affiliated (most commonly Episcopal).
Top Ranked Private High Schools Belonging to Independent Schools Association of the South West (ISAS) in Oklahoma (2025-26)
School
Location
Quick Facts
Casady School![Casady School Photo - Casady School includes four divisions: Primary for Pre-K, Lower for grades 1-4, Middle for grades 5-8, and Upper for grades 9-12.]( "Casady School Photo - Casady School includes four divisions: Primary for Pre-K, Lower for grades 1-4, Middle for grades 5-8, and Upper for grades 9-12.")
(Episcopal)
9500 N Pennsylvania Ave
Oklahoma City, OK 73120
(405) 749-3200
Oklahoma City, OK 73120
(405) 749-3200
Gr: PK-12 | 1,049 student Avg. class size: 13 students Sports: 15 | Extracurrculars: 9 Tuition & acceptance rate listed
1800 NW 122nd Street
Oklahoma City, OK 73120
(405) 936-3009
Oklahoma City, OK 73120
(405) 936-3009
Gr: PK-12 | 955 students Avg. class size: 13 students Sports: 13 | Extracurrculars: 12 Tuition listed
Holland Hall![Holland Hall Photo - More space to learn and grow. Here our Primary School students make some campfire S'Mores during an outdoor unit. S'More?! How can I have more when I haven't had any?! *Bonus points for knowing the quote*]( "Holland Hall Photo - More space to learn and grow. Here our Primary School students make some campfire S'Mores during an outdoor unit. S'More?! How can I have more when I haven't had any?! *Bonus points for knowing the quote*")
(Episcopal)
5666 E 81st
Tulsa, OK 74137
(918) 481-1111
Tulsa, OK 74137
(918) 481-1111
Gr: NS-12 | 1,032 student Avg. class size: 18 students Sports: 16 | Extracurrculars: 22 Tuition & acceptance rate listed
2433 W 61st Street
Tulsa, OK 74132
(918) 446-3553
Tulsa, OK 74132
(918) 446-3553
Gr: NS-12 | 616 students Avg. class size: 13 students Sports: 8 | Extracurrculars: 13 Tuition listed
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