William Thompson Kirkpatrick (10 January 1848 - 22 March 1921) was an Irish teacher and grammar school headmaster. He is best known for having been the tutor of the two Lewis brothers from Belfast, Warnie Lewis and C.S. Lewis. C.S. Lewis, who would later become well known as a literary critic, novelist, and Christian apologist, lived as a resident pupil with Kirkpatrick from 1914-1917. In his autobiography, Lewis reports that he was significantly influenced by his tutor.
Kirkpatrick was born to an agricultural family in 1848 at Boardmills, County Down. He was educated at Queen's College, Belfast in 1865-1868. At first following an ambition to be called into the Presbyterian ministry, Kirkpatrick followed up his college studies with three years of theological training at Assembly's College, Belfast, the standard place of instruction for ordination into this denomination in Ireland. He also became a grammar school teacher at the Royal Belfast Academical Institution. He was licensed by Assembly's in 1871. Instead of accepting a call to a pulpit, however, he continued to teach. Kirkpatrick's biographer Ian Wilson believes that Kirkpatrick quickly developed a strong reputation for aggressive teaching leadership; at any rate, in late 1872 the young "Inst" teacher put in his name as the prospective headmaster of the newly established County Armagh grammar school, Lurgan College. After a three-year delay, Kirkpatrick was taken on in January 1876 as the young College's 28-year-old headmaster.
Lurgan at the start of 1876 had only 16 pupils. The College trustees asked their selectee to take steps to ensure the long-term survival of the College. Kirkpatrick aggressively recruited day boys and boarding pupils, and enrollment increased to 73 in 1882. Kirkpatrick was helped in his responsibilities, starting with his marriage in July 1881, by his wife Louisa Smyth.
At full size, the College was able to support a Headmaster couple, two Assistant Masters, and a steward. The staff and Headmaster shared out teaching responsibilities, which centered on drilling the pupils in Latin, Greek, modern languages and mathematics in preparation for university. Despite its small size, Lurgan came to be seen as an Irish grammar school of the first rank, and its pupils collected more than their numerical share of the honours and prizes distributed to Irish students in those days. One of the College's students was the future Belfast solicitor Albert Lewis, who studied there in 1879-1880.