For the 2026 school year, there are 5 private schools belonging to Independent Schools Association of the South West (ISAS) serving 4,250 students in Oklahoma. You can also find more schools membership associations in Oklahoma.
The top-ranked private schools belonging to Independent Schools Association of the South West (ISAS) in Oklahoma include Westminster School, Casady School, and Heritage Hall.
The average acceptance rate is 58%, which is lower than the Oklahoma private school average acceptance rate of 86%.
40% of private schools belonging to Independent Schools Association of the South West (ISAS) in Oklahoma are religiously affiliated (most commonly Episcopal).
Top-Ranked Private Schools Belonging to Independent Schools Association of the South West (ISAS) in Oklahoma (2026)
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 students 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 students 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
600 NW 44th Street
Oklahoma City, OK 73118
(214) 796-1156
Oklahoma City, OK 73118
(214) 796-1156
Gr: PK-8 | 598 students Avg. class size: 11 students Sports: 6 Tuition listed
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