Ong was the founder/pioneer of four schools in the Manjung district, namely, Chung Cheng Primary School in Sitiawan; Nan Hwa High School in Sitiawan; Ping Min Free School in Lumut; and Dindings High School in Lumut. These four schools are now renamed SJK (C) Chung Cheng, SMJK Nan Hwa, SJK (C) Ping Min and SMJK Dindings, respectively. In 1961, Nan Hwa High School was split into SMJK Nan Hwa, a public school and Nan Hwa Private High School. Thus, from the original four schools that Ong founded/pioneered, there are now five schools operating in Manjung District. Details of the founding of these schools are found in the book, Wang Jianshi, Ong Eng-Joo: No Other Way Out - A Biography of Ong Seok Kim. Petaling Jaya, Malaysia: Strategic Information and Research Development Centre, 2013.
Chung Cheng Primary School, Sitiawan Chung Cheng Primary School was better known in its early days until the 1950s as the “
Hokkien School”. Ong was elected as Secretary of the School Board in 1920 and remained in that position until 1927 when he was elected Chairman. He served on the board for more than 30 years, with 20 years (1927-1934; 1936-1939 and 1945-1955), as Chairman. During the period, Ong was involved in the development of Chung Cheng - the hostels, the school hall, classrooms and the establishment of the high school section. He raised funds for the school. Fundraising brought Ong to towns in many parts of Malaya, to Singapore and Betong, Thailand. After the Japanese invasion of Malaya in December 1941, Ong continued going around Malaya collecting donations, visiting Betong,
Grik,
Lenggong,
Kuala Kangsar,
Taiping and
Keroh to raise funds for the school. It is estimated that he approached and raised funds from more than 10,000 donors in more than 70 towns; some he visited on several occasions.
Nan Hwa High School, Sitiawan Before 1935, there were four dialectic schools in Manjung District, each with its own junior high school section catering for their own clan - Chung Cheng for the Hokkien, Kuok Min for the
Kutien, Uk Dih for the
Hockchew (
Fuzhou) and Min Teik for the
Hockchia. In 1935, Ong and local community leaders launched a proposal to merge the junior high school section of the four schools to form a Junior and High School. The community leaders chose the name "Nan Hwa" to remind students that their ancestors migrated from China to settle in Nanyang. A meeting was convened in late 1935. At the meeting, Ong was elected the first Chairman of the School and Chairman/Secretary of the School Building Construction and Building Fundraising Committee. Efforts were then made to find a neutral venue. Ong personally donated $3,000 to purchase a piece of land along Kampung Koh Road. This is the site where SMJK Nan Hwa now sits. In addition, he donated money to build three classrooms. As Chairman of the Fundraising Committee, Ong solicited donations from the public and businesses in towns throughout Malaya and in Singapore to build new classrooms, teachers' room, and amenities and office administration block. A donation was made by the Haw Par Brothers,
Aw Boon Haw and
Aw Boon Par, in 1939 to build a school hall. Rev. T.C. Nga, noted that ". . . a substantial donation from Haw Par Brothers was solicited by Mr Ong Seok Kim, and a school hall was erected and named after the donors." A couple of years after the school started, the Japanese occupied Malaya. During the
Japanese Occupation, the school premises, facilities and compound were badly damaged. Immediately after the Japanese Occupation, Ong was re-elected Chairman of the School Board in 1946 and 1947; and Chairman of the Building and Fundraising Committee. The immediate task was to restore/rebuild its premises and its facilities and amenities. Rev.T.C. Nga noted: "The task was gigantic then. In the midst of the then prevailing chaotic situation, some community leaders led by Mr Ong Seok Kim visited Nan Hwa High School, with the purpose of reopening the institution for classes to resume as soon as possible. The re-organised Management Committee of Nan Hwa High School, Sitiawan, under the chairmanship of Mr Ong Seok Kim, . . . raised the needed funds to repair and renovate the existing premises and also to build additional classrooms to meet the fast growing student population after the War. By 1947, Junior Middle classes in both Arts and Sciences were conducted . . . In addition to conducting Junior Middle classes in both Science and Arts, the School . . . also conducted Simplified Teachers’ Training Course..."
Ping Min Free School, Lumut In 1951 Ong, together with Saw Cheng Chor (), founded Ping Min Free School in Lumut, a coastal town in the Manjung District. Ong raised funds, planned the school layout and managed its construction. He was elected the school's first Chairman, serving between 1951 and 1956. He was a member of the School Board till 1962.
Dindings High School, Lumut In June 1953, Ong, then 69 years old, and Shen Ding-yuan (), founded Dindings High School. Ong submitted the application for registration of the school to the Department of Education in Ipoh. After a start-up period of seven months, the school was born with an opening ceremony held on 11 January 1954 at the school hall of Ping Min. Only two Junior Middle 1 (Form 1) classes were started at the beginning, with an enrolment of 60 students. Ong was elected the first Chairman of the School Board, serving between 1954 and 1958. As Chairman of the School Board and in particular as Chairman of the School Fundraising Committee for nine years since the start of the school, Ong led a campaign to raise funds to upgrade and expand the school to accommodate senior middle classes. More than $200,000 was collected in donations from the local community and donors from over 70 towns located outside of Manjung District. In his diary, Ong recounted the fundraising activity as “full of painfully hard work”. He recorded that the School Fundraising Committee went through three fundraising trips to over 70 towns throughout Malaya and to Singapore to solicit for donations. From 8 September 1959 to 18 October 1960, a total of 213 days were spent in fundraising activities. With the donations, the school was upgraded with the construction of new classrooms, a library, and a school hall and the establishment of senior middle classes. The opening ceremony, and a fun fair, was held on 9 October 1960. Members of the Committee, led by Ong, had financed their own expenses in their trips out of town to solicit for donations. Their contributions were recognised through the construction of a plaque which was erected in the
Lee Kong Chian School Hall and acknowledged in the School's 1961 Memorial Magazine, edited and published by Ong.
Other Schools In the 1930s, 1940s and 1950s, Ong represented Chinese schools in the Manjung District in various activities and functions pertaining to Chinese education such as the training of Chinese school teachers and raising their employment conditions, in fundraising, and in meetings to raise academic standard and organizing and conducting sporting activities. Records of Khuen Hean Primary School [now known as SJK (C) Khuen Hean],
Changkat Keruing, show that Ong made early donations to the school in 1936 for its upgrade, maintenance and purchase of school equipment. For his contribution, he was installed an honorary committee member of the School Board. In 1936 and 1937, Ong made donations and played a role in helping Kuok Min Primary School [now known as SRJ (C) Kuok Min] in Sitiawan, to raise funds for its expansion and repair, purchase of school equipments and maintenance of school facilities and amenities. A total of $10,000 was raised in the fundraising campaign. In 1941, Ong was elected Vice-Chairman of the School Board, Pei Ching Primary School [now known as SJK (C) Pei Ching] in
Beruas, Manjung District. In 1946, he founded Betong Primary School in Thailand where he had some rubber land. He was an adviser and an Inspector of the School. He was also Honorary Chairman of the School Board of Pei Min Primary School [now known as SJK (C) Pei Min] in
Segari, and Eng Ling Primary School [now known as SJK (C) Eng Ling] in Lumut, all located in the Manjung District. He was a member of the School Board of Simpang Empat English School (aka
Gandhi School) in Sitiawan for many years. ==Personal life==