Peter Maiden is stepping down as leader of Operation Mobilisation after 10 years in the role.
Lawrence Tong was appointed during OM's recent International Leaders Meeting in Bangkok, Thailand.
Originally from Singapore, Tong previously served as Director of OM's ship Logos II, before pioneering the work of OM in China.
He will assume responsibility on 1 September 2013.
Commenting on the appointment of his successor, Maiden said: "I will be delighted to hand over the reins to Lawrence Tong. I think this is the right time for an individual who has the necessary gifts, and is from the Global South to take the helm of the movement."
Maiden's career with OM spans nearly 40 years. He and his wife Win joined OM in 1974, leading the work of OM UK until 1985, when he became the first Associate International Director.
"It has been an enormous honour and joy for Win and I to serve in this capacity. We've had a brilliant team around us and we owe a great debt to them," he said.
Tong visited the Logos when it came to Singapore in 1974 and went on to join the OM ministry team on one of the mission agency's other ships, Doulos, in 1978.
It was here he met his American wife-to-be, Susan, prior to serving for 10 years in various OM fields - including India, Bangladesh, and OM USA.
Tong's leadership has included serving on the Board of OM Singapore (1995–2001); OM Director for Taiwan (1999–2001); Director of Logos II (2001-2005); and financial development with OM Ships USA. Since 2006,
He has led the growing work of OM China, with significant focus on welfare and agricultural programmes alongside local partners in the Sichuan region following the 2008 earthquake.
"My heartbeat is to encourage OM to remain true, both to the Gospel and to our core values, as we seek with passion to bring hope to the lives of men and women and boys and girls in almost every part of the world," he said.
"For my part, I will continue to strive to give back to OM what the Lord has given to me, so that I, and we together, our generation of OMers, may be even more worthy of His calling."