Josias Leslie Porter (4 October 1823 – 16 March 1889) was an Irish Presbyterian minister, missionary and traveller, who became an academic administrator.

[1] In 1859, Porter returned home on furlough, and in July 1860 was appointed professor of biblical criticism in Assembly's College, Belfast, in succession to Robert Wilson.

Porter, from the time of his appointment as professor, took a leading part in the work of the church courts, and in 1875 was elected Moderator of the General Assembly.

[1] In 1878, Porter was appointed by government one of the two assistant-commissioners of the newly established board of intermediate education for Ireland.

In virtue of his office he became a member of the senate of the newly created Royal University of Ireland, which in 1881 conferred on him the degree of D.

[1] In 1855, Porter published his first book on the Middle East, Five Years in Damascus, in which he related his life there, and journeys to destinations in the Ottoman Empire, including Palmyra, the Hauran, and Lebanon.

He contributed extensively to the edition of John Kitto's Cyclopædia of Biblical Literature which was begun in 1862; nearly all the geographical articles on places in Palestine were by him.

David Hamilton, honorary secretary of the Irish Presbyterian Jewish Mission, were printed in the pages of the Missionary Herald.