在 Mission/Organization Index 中，以 U 開頭的條目
- Union Church, Hong Kong
- Union Church, Peking
- Union Evangelistic Committee
- Union Presbyterian Church of South Fukien
- United Brethren in Christ
- United Christian Missionary Society
- United Church of Canada
- United Evangelical Church Mission
- United Free Church of Scotland
- United Free Gospel Missionary Society
- United Lutheran Church of America
- United Methodist Free Church Mission
- United Methodist Mission
- United Presbyterian Mission
- United Society for Christian Endeavor
- United Society for Christian Endeavor in China
- United Society for Christian Endeavor in Japan
- United Society of Womenʹs Boards
- Universal Christian Council for Life end Work
- Universitiesʹ Mission
- University of Pennsylvania Mission
- Utrecht Missionary Association