William Clarke Alexander, D.D. (September 6, 1850 – May 26, 1919) was a Presbyterian minister born in Lewistown, Pennsylvania, who made his profession of faith as a youth, graduated from Lafayette College, and completed theological training at Princeton Theological Seminary before being ordained in 1876. He served as pastor in several congregations—including Pequea, Pennsylvania; Middletown, Delaware; Matawan, New Jersey; West Street Church in Washington, D.C.; and Roswell, New Mexico—and received an honorary Doctor of Divinity from Lafayette College in 1893 while also authoring church histories. After retiring from active ministry he lived in the Philadelphia area and died in Overbrook, Pennsylvania; he was buried at Easton Cemetery in Easton, Pennsylvania.