Theologian. William Culbertson III (November 18, 1905 — 1971) was notable as a Pastor, a Bishop of the Reformed Episcopal Church and the fifth President of the Moody Bible Institute in Chicago, Illinois.

Culbertson was born in Philadelphia on November 18, 1905, to William and Lyda (Roper) Culbertson. He graduated from the Reformed Episcopal Seminary in Philadelphia, Pennsylvania with a diploma in 1927. After graduation, he was ordained to the Diaconate of the Reformed Episcopal Church and served as Minister-in-Charge of Grace Reformed Episcopal Church, Collingdale, Pennsylvania. He was ordained a Presbyter the following year. On March 16, 1929, Culbertson married Catherine Gantz. In 1930 he accepted the call to serve as Rector of St. John's-by-the-Sea Reformed Episcopal Church in Ventnor, New Jersey. he moved to the Church of the Atonement (Reformed Episcopal) in Philadelphia in 1933. He received his Bachelor of Science degree from Temple University in 1939, at which time the seminary exchanged his diploma for a Bachelor of Divinity and conferred upon him an honorary Doctor of Divinity. Culbertson was elected Bishop of the New York and Philadelphia Synod of his denomination in 1937 and served in that position until he assumed the duties as Dean of Moody Bible Institute in Chicago, Illinois in 1942.

Six years later, upon the death of Will H. Houghton, the Trustees elected him to be its next President. He was the second Reformed Episcopalian to hold this position. Under his administration the school's curriculum was strengthened and a degree program was adopted. Its day school enrollment grew to over 1,000 students. Five major buildings were added to the Chicago campus, as well. Missionary technical courses, including aviation and radio, were also added to the curriculum. Culbertson served until 1971, when he was appointed the school's first Chancellor. He was also in high demand as a Bible Conference speaker around the world. He served for a time as the President of the Accrediting Association of Bible Colleges.