William Edward Hearn (21 April 1826 – 23 April 1888) was an Irish university professor and politician. He was one of the four original professors at the University of Melbourne and became the first Dean of the University's Law School.
Hearn was born in Belturbet, County Cavan, Ireland, the son of Reverend William Edward Hearn (a curate and later a vicar) and Henrietta Hearn (née Reynolds). He was the second of seven sons in the family. Hearn was educated at Portora Royal School in Enniskillen, Ireland and later studied at Trinity College at the University of Dublin from 1842. There he was highly successful in his study of classics, logic and ethics, graduating with a Bachelor of Arts degree in 1847. Following his studies in arts, Hearn also studied law, at Trinity College and later at King's Inns in Dublin and Lincoln's Inn in London, and was admitted to the Irish Bar in 1853.
Hearn's teaching career began in 1849, when he was selected as a professor of Ancient Greek at the Queen's College, Galway, which had been established a few years earlier.
In 1854, a London-based committee of the newly established University of Melbourne selected Hearn as one of four original professors of the University. Hearn was to teach subjects including modern history, modern literature and political science in the Faculty of Arts, although at times during his career he also taught classics. Hearn moved to Melbourne, Australia in 1855, where he took up residence in the rooms provided on the university campus. Hearn's students at Melbourne included Alfred Deakin, H.B. Higgins, Isaac Isaacs, Alexander Sutherland, Samuel Alexander and Thomas Webb.