The Old Order River Brethren are a small Old Order Christian denomination with roots in the Mennonite church and German pietism through the Schwarzenau Brethren.
The denomination began about 1778 in Pennsylvania. It shares an early history with the Brethren in Christ Church. A group of brethren near the Susquehanna River that had previously separated from the Mennonites became known as the River Brethren. In 1856, a group left the larger body of River Brethren and established a separate, more conservative group. They were sometimes referred to as the York Brethren or Yorkers, because most of the members in 1843 were located in York County, Pennsylvania. This minority group believed the majority of the church was becoming lax in non-conformity and non-resistance, and desired to return to old doctrines and traditions. With the emergence of the Old Order groups among the Amish (Old Order Amish forming 1862-78), the Mennonites (Old Order Mennonites, 1872-1901) and the German Baptist Brethren (Old German Baptist Brethren 1882) in the late 1800s they defined themselves also as "Old Order".
Between 1921 and 1961 four splits occurred in the group, mostly about the use of cars, leaving the Old Order River Brethren divided into five subgroups. Three of the five groups reunited between 1969 and 1977 so that there are three subgroups until today.
Traditionally meetings for worship were held in the homes of the members. In recent times, meetinghouses and public buildings are also used for church services. Ministers are un-salaried and there is no formal training for preachers. A traditional congregation has a bishop, two ministers, and one or two deacons.