Albert Henry Newman, son of John Blackstone and Harriet (Whitaker) Newman, was born in the Edgefield District of South Carolina on August 25, 1852. He is said to have learned to read at the age of three. Because public schools were not available, his earliest formal education was through private schools, usually taught by the local pastor. When the family moved to Thomson, Georgia, at the end of the Civil War, Newman came under the tutelage of Rev. Epenatus Alexis Steed, who prepared Newman so well that he was able to enter the junior class at Mercer University in September 1869 and graduate first in his class of fifteen in 1871. Newman enrolled at Rochester Baptist Theological Seminary in 1872, after a year of teaching elementary school. He graduated in 1875 with a specialty in Hebrew and exegesis of the Old Testament. He intended to further his education in Germany, but instead decided to attend the Southern Baptist Theological Seminary, then located at Greenville, South Carolina. There he studied languages and the Old and New testaments with Crawford Howell Toy and John Albert Broadus. Newman received his LL.D. from Southwestern Baptist University in 1883 and his D.D. from Mercer University in 1885.

He was acting professor of church history (1877–80) and Pettingill Professor of Church History (1880–81) at the Rochester Baptist Theological Seminary; subsequently, he served as professor of church history at Toronto Baptist College (1881–91). In 1891 this institution became McMaster University, and Newman continued to teach there until 1901, when he went to Baylor University. There he taught for six years and assisted Benajah Harvey Carroll in organizing a theology department, which in 1907 or 1908 became an independent seminary with Carroll as president and Newman as dean. In 1910 the seminary, called Southwestern Baptist Theological Seminary, was relocated near Fort Worth. Carroll's failing health and conflicts over the curriculum led to Newman's resignation around 1913. He returned to Baylor where he again taught church history until 1921. During this time he was also a visiting professor in comparative religions at Vanderbilt University (1917–18). In 1921 he received an honorary LL.D. at his class reunion at Mercer University, which had recently been moved to Macon, Georgia. There he was offered the chair of church history in the reorganized seminary. In 1926 he was visiting professor at the University of Chicago, where he had also taught in 1906. In 1927 Newman was made professor emeritus at Mercer, and that same year he returned to McMaster University, where he taught until his retirement in 1929.

Newman contributed hundreds of articles and reviews to journals, periodicals, encyclopedias, and dictionaries. His major works include A History of Anti-Pedobaptism: From the Rise of Pedobaptism to A.D. 1609 (1897; reprinted 1902), A History of the Baptist Churches in the United States (first published in 1894, with numerous subsequent editions), and A Manual of Church History (in two volumes, first published in 1899 and 1902, again with numerous subsequent editions). Newman edited A Century of Baptist Achievement (1901) and Memoir of Daniel Arthur McGregor (1891). He was a pioneer in presenting the Anabaptists in a positive light. His work provided a new understanding of the origin of the Baptist Church. Newman mastered several ancient languages and became an expert on early Christianity, especially the dissenting sects. His Manual of Church History, though now outdated, served for years as the standard text for church history courses in many Baptist universities and seminaries. Newman married Mary Augusta Ware of Seale, Alabama, on July 15, 1873, during his time as a Rochester seminary student. The couple had four children. Upon retirement in 1929, the Newmans moved to Austin, where they resided with their daughter and son-in-law, Dr. Frederick Eby. Newman died on June 4, 1933, from complications sustained after being struck by an automobile. He was buried in Austin Memorial Cemetery.