O'ong was born on July 28, 1953 in Bondowoso, East Java, Indonesia. Actually, his real name is Sumaryono, but since childhood his friends gave him the name of 'O'ong Maryono' and he has maintained until his last day.
Since he was 9 years old. O'ong learned pencak silat Madura and Bawean and practiced Kuntao. He first master was his grandfather, Matrawi, who introduced him to the style Macan Kumbang. Later he became a member of the Elang Putih school under master Handoko. When pencak silat became a competitive sport in 1973, O'ong Maryono started his career as "fighter" winning the regional championships in the regency of Bondowoso.
In the same year he moved to Jakarta where he also practiced karate, judo, aikido, ju jitsu and tae kwon do, besides training pencak silat in the school of the Keluarga Pencak Silat (KPS) Nusantara where he practiced with masters Muhammad Hadimulyo and Bambang TW Anggono. In 2012 he was granted the white belt as Pendekar Paripurna, the highest level in KPS Nusantara.
From 1979 until 1987 he won many national and international competitions. Among his international achievements, he became twice world champion pencak silat in the free class in 1982 and 1984. He also won the first prize in the same category in the South East Asia Games XIV held in 1987 in Jakarta.
In between 1982 and 1985 O'ong also dominated national Taek Won Do competitions as champion in the heavy weight class. After he concluded his carrier as athlete because of age limits, O'ong pencak silat in Brunei Darussalam, Holland, the Philippines, and more recently in Thailand where he coached the Thai national team on various SEA Games Competitions. He also played in martial arts movies in Indonesia, including Tutur Tinular, Jaka Swara and Saur Sepuh.
O'ong also began a profession as freelance writer and researcher on martial arts. In 1998 he published a book entitled "Pencak Silat Merentang Waktu" (literally "Pencak Silat Stretched Across Time) on the socio-cultural aspects of pencak silat and its historical development, which has been translated into English as “Pencak Silat in the Indonesian Archipelago”. Both versions have received wide public recognition and have become main sources of knowledge on pencak silat.
At the time of his death he was working on a cartoon version of KPS Nusantara techniques to be published shortly.
He was responsible for public relations at the International Pencak Silat Federation (PERSILAT) and a founder and Chief Governing Officer of the Lembaga Pengembangan dan Pelestarian Budaya Indonesia (Association for the Development and Conservation of Indonesian Culture) entrusted with the organization of Festival Pencak Silat Malioboro and other activities to promote pencak silat as part of Indonesian culture.
After a brave fight against cancer, he died in Singapore on 20 March 2013 embraced by his wife, Rosalia (Lia) Sciortino and surrounded by family and friends.
O'ong & Lia at the Taj Mahal, Agra, India, November 2012