OKI International School, Wattala being the parent school was established in September 1998.

Presently we offer classes for students from Play Group to A/L (Commerce Stream & Science Stream). The school operates in two locations. Pre-School to Grade 7 classes (Junior Section) are conducted at No.80, Old Negombo Road, Wattala. Pre-School to A/L classes are conducted at the main school, Wattala.

The school has a library, IT lab with Internet facilities and a well- equipped Science Lab which are utilized by classes up to A/L. The school has arranged a plethora of associations and clubs such as English, Sinhala and Tamil Associations, Science and Commerce Associations, Prefects Unit, UN Club, Reading Club, Media and Broadcasting Club, Chess Club, Social Service Club, Aviation Club, Robotics Club, Debating Club, Gavel Club, Boys Scouts Unit, Cubs Scouts Unit and Girl Guides Unit for the skill development of the students.

In the field of extracurricular activities the school also offers Swimming, Cricket, Netball, Basketball, Badminton, Karate, Table Tennis and Athletics for its students.

OKI International School, Kandana was established in January, 2002.

Presently we cater to students from Play Group to A/L (Commerce Stream). Our branch operates in two locations. Pre-School to Grade 2 classes are conducted at No.23 Church Road Kandana (as a feeding School). Pre-School to A/L (Commerce Stream) classes are conducted at Hapugoda No.286/2 Ganemulla Road Hapugoda Kandana.
The school has a library, IT lab with 25 computers with Internet facilities and a science lab with facilities to conduct practical up to Ordinary Level.

The school has arranged clubs and societies such as UN Club, Reading club, Media club, English Literary Association, Commerce Association, Science Association and scouting.

In the field of extracurricular activities the school also offers swimming, cricket, netball, badminton, chess, karate and athletics for its students.

OKI International School, Biyagama was established in January, 2004.

We conduct classes from Play Group to G.C.E. Ordinary Level in our branch.
At OKI International School Biyagama branch, we follow the National stream in English medium.

The school has a library, an air conditioned IT lab with 25 computers with internet facilities and a Science lab with facilities to conduct practical lessons up to Ordinary Level.

The school gives the opportunities for the students to get themselves involved in clubs and societies such as UN Club, Media and Broadcasting club, English Literary Association, Sinhala Literary Association, Eco-Friends, Social-Service, club and Scouting. The school also offers swimming, cricket, netball, badminton, chess, karate and athletics for its students.

OKI International School, Kiribathgoda was established in September, 2003 with 21 students and 4 Teachers.

The school conducts classes from Pre-School to Ordinary Level examination in the National Curriculum and in Science and Commerce streams in Cambridge Examinations supported by a highly proficient and skilled teaching staff.

The school has an IT laboratory with modern facilities, a Science Laboratory and a library.
Our school provides holistic education and development of the students. Our students have participated and excelled in many sports activities like Athletics, Badminton, Swimming, Karate and Cricket at national and international level especially in Karate.

Many Co-curricular activities like English Literary Association, Science Association, Commerce Association, Social Club, Media Club, Green Club, Cub Scouting/Scouting, Little Friends/Guides, Chess have been formed and are actively pursued by our students with Dramas, Science Exhibitions and other initiatives taken up by the Associations. These have kindled the students’ enthusiasm and interest in such activities which are considered equally important alongside academics in providing students holistic school experience.

OKI International School Kotikawatte which was established in September 2006, was later relocated in its own state of the art facility in Kaduwela on the 6th of September 2018.

Kaduwela School is located in close proximity to Kaduwela Junction and is equipped with spacious classrooms, play areas, air conditioned IT Laboratory with Internet facilities, Science Laboratory, Library, Robotics Room, Aesthetic Rooms and an Audio-visual Room.

It conducts classes from Preschool upto Ordinary Level both in Cambridge Curriculum (IGCS) and National Curriculum in English Medium. The students have the choice of selecting between these two curricula in Grade 8 to proceed upto O/Level.

The school offers extra curricular activities such as cricket, swimming, basketball, badminton, chess, karate and athletics.

It also holds various student clubs and societies to help personality development, teamwork and harmony, such as Media Club, Debating Club, Prefects' Guild, English Literary Association, Sinhala Literary Association, Buddhist Society, Hindu Society, Science Society and Commerce Society.

Further, it offers Cambridge English Young Learners Courses which lead to Cambridge YLE Exams in three levels: Starters, Movers and Flyers

OKI Negombo branch is established in July 2007 with two children in Play-Group class and one teacher. It caters hundreds of students at present providing academic excellence from Play-Group to O/L in both National and Cambridge Curriculums.

A/S and A/L classes have been started from August 2017 in both Science and Commerce streams.
OKI International School, Negombo provides an unbelievable opportunity for the students by providing all the facilities such as Computer Lab, Science Labs and a Library with e-library facilities at a very reasonable school fee.

OKI has become the pioneers of grooming the students by its active functioning of Associations and Clubs. English Literary Association, Science and Commerce Association, Media club, Social Service Association and Drama Club are some of such communities where children learn leadership and life skills up to a great extent.

In the field of extracurricular, the school offers swimming, cricket, netball, badminton, chess, karate and athletics for its students.

Special and advance methods of teaching, meeting the curriculum goals, special attention given to each individual accentuate OKI International School significantly.