in the Bahāʾī faith, any of numerous administrative units that conduct an extensive work of missions, publication, education, and general philanthropy. Spiritual assemblies consist of nine members elected or designated annually on the local, national, and world levels during the holy days (April 21, April 29, May 2) commemorating the declaration of the founder's mission. Since they are said to be invested with their authority by God himself, the members of the spiritual assemblies have absolute jurisdiction over their electorates and are not answerable to them for their decisions and actions. Financial support comes from voluntary contributions from the community.

A local spiritual assembly exists in any community of nine or more Bahāʾī members. In the early 1980s there were some 26,000 local assemblies. National spiritual assemblies—numbering 130 by the early 1980s—appear when there are enough local assemblies in a country to elect a 19-member convention, which in turn will elect the nine members of the national group from among all Bahāʾīs in the country. World leadership of the faith was held by Shoghi Effendi Rabbani (Shoghi Effendi Rabbānī) as Guardian of the Cause of God until his death in 1957; since 1963 it has been assumed by the highest spiritual assembly, the Universal House of Justice, a body elected by the national spiritual assemblies and possessing the sole right to institute new laws or abrogate the old laws laid down in Bahāʾī sacred scriptures.