Joseph Augustus Seiss (March 18, 1823 – June 20, 1904) was an American theologian and Lutheran minister. He was known for his religion writings on pyramidology and dispensationalism.
Seiss was born in Graceham, Frederick County, Maryland, to an agricultural family; his interest in religious studies reportedly began in childhood. Seiss was confirmed at age 15 as a member of the Moravian Church, and determined to pursue the ministry. Beginning in 1839, Seiss enrolled at Gettysburg College in Pennsylvania for a year or two of studies, but completed his theological courses by private study. He was licensed to preach in 1842 by the synod of Virginia, and ordained to a Lutheran ministry in 1844. Seiss held pastorates in Virginia and Maryland until 1858, when he accepted a position at St. John's English Lutheran Church in Philadelphia. In 1875, Seiss was elected pastor of the newly established Lutheran Church of the Holy Communion in western Philadelphia.
His contemporaries described him as "an eloquent pulpit orator" and said his "style is clear, ornate, attractive, and forcible". Periodicals of the day mention his speeches at New York's Steinway Hall and other prominent venues. Seiss was first published when he was 22 years old, and his works were often reviewed in literary and theological journals. A 1904 New York Times abstract describes Seiss as "one of the foremost men of the Church" and as "one of the founders of the General Council in 1867".