The Omaura School of Ministry is located in the Eastern Highlands of Papua New Guinea (PNG), at an altitude of 4,650 feet (1,417 meters). It was originally established as the Omaura Training School, “for the purpose of training workers to carry the message to the multiplied thousands of the great inland who have not yet been reached by any mission influence.”
Daniel Kayode Omoleye was a pastor, church planter, evangelist, and church administrator from Nigeria.
Abel Nyakundi Onchoke was a pastor, educator and administrator from Kenya.
Ondo Mission, formerly South West Nigeria Conference, was organized in 1998, and reorganized and renamed in 2013. Ondo Mission covers the present Ondo state of the Federal Republic of Nigeria.
Joseph Shem Onyango was a church pioneer, pastor, preacher, evangelist, and marriage counselor from Tanzania.
Open Heart International (OHI) is a medical outreach program originally started by Sydney Adventist Hospital in 1986. It has conducted more than 188 surgical projects in 16 countries. OHI’s volunteer teams provide cardiac, plastic, reconstructive, orthopedic, women’s health, and eye surgery.
Ole Oppegard, a pioneer from Norway, served in Argentina as a literature evangelist and as the first Adventist missionary in South America dedicated to medical missionary efforts.
Alfredo Ordóñez Withol dedicated his life to pastoral and teaching ministry in Nicaragua and Honduras.
The Oriental Watchman Publishing House is the first and only Seventh-day Adventist publishing house in India. It maintains its own printing facilities in Pune, India, and is operated by the Seventh-day Adventist Publishing Association (Pvt. Ltd.), a company owned by the Southern Asia Division of Seventh-day Adventists.
Eldama Ravine is a town in Baringo County, Kenya, a few miles north of equator. It is the cradle of Adventism in the northwest part of Kenya that today has 30,078 church members who worship in 352 organized churches.
Embu East is a county in Kenya. Adventism started in Embu East at a place known as Runyenjes at a social hall built by Chief Mugucu wa Makathwa. It is the cradle of Adventism in the northeast part of Kenya that today has 24,897 church members who worship in 369 organized churches.
John Babajide Oriola was one of the Adventist pioneering ministers in Nigeria.
Organized in 1974 and reorganized in 2001, Orissa Section is part of the Central India Union Mission of the Southern Asia Division of Seventh-day Adventists.
The pioneer missionary work of Orley Ford in Peru, Ecuador, Guatemala, Costa Rica, and El Salvador has left a lasting mark in these countries.
Jonathan Trumbull Orton was an early convert to Sabbatarian Adventism in Rochester, New York.
William Adolphus Osborne was a leading pioneering Caribbean Adventist educator and administrator who worked and inspired Adventist youth for more than 40 years between 1930 and 1975.
Nahashon Nyasimi Osebe was the first Adventist lay evangelist to work among the Kipsigis.
John Oss (史約翰; Pinyin Shǐ Yuēhàn) was an Adventist colporteur, minister, administrator, and missionary to China. He was the official pioneer missionary to open the first wave of the denomination’s work in Mongolia. He witnessed wars in China and was a prisoner of war.
Melvin and Mae Oss were missionaries to India. Melvin was the founder of Camp MiVoden and co-founder of Upper Columbia Academy.
Missionary to China, colporteur, fundraiser for Adventist and Red Cross hospitals and educational institutions, writer, and public speaker. Oss witnessed the Shanghai incident and the Second Sino-Japanese War in Shanghai and was a World War II Japanese concentration-camp survivor. Oss with her husband John returned to China after recuperating in the United States and stayed until they were forced to leave by the Communist Chinese government in 1950.