Coleridge was born on 21 October 1772 in the Town of Ottery St Mary in Devon, England. Samuel's father was the Reverend John Coleridge (1718–1781), the well-respected vicar of St Mary's Church, Ottery St Mary and was headmaster of the King's School, a free grammar school established by King Henry VIII (1509–1547) in the town. He had previously been master of Hugh Squier's School in South Molton, Devon, and lecturer of nearby Molland. John Coleridge had three children by his first wife. Samuel was the youngest of ten by the Reverend Mr. Coleridge's second wife, Anne Bowden (1726–1809), probably the daughter of John Bowden, Mayor of South Molton, Devon, in 1726. Coleridge suggests that he "took no pleasure in boyish sports" but instead read "incessantly" and played by himself. After John Coleridge died in 1781, 8-year-old Samuel was sent to Christ's Hospital, a charity school which was founded in the 16th century in Greyfriars, London, where he remained throughout his childhood, studying and writing poetry. At that school Coleridge became friends with Charles Lamb, a schoolmate, and studied the works of Virgil and William Lisle Bowles. In one of a series of autobiographical letters written to Thomas Poole, Coleridge wrote: "At six years old I remember to have read Belisarius, Robinson Crusoe, and Philip Quarll – and then I found the Arabian Nights' Entertainments – one tale of which (the tale of a man who was compelled to seek for a pure virgin) made so deep an impression on me (I had read it in the evening while my mother was mending stockings) that I was haunted by spectres whenever I was in the dark – and I distinctly remember the anxious and fearful eagerness with which I used to watch the window in which the books lay – and whenever the sun lay upon them, I would seize it, carry it by the wall, and bask, and read."
Coleridge seems to have appreciated his teacher, as he wrote in recollections of his school days in Biographia Literaria:
I enjoyed the inestimable advantage of a very sensible, though at the same time, a very severe master [...] At the same time that we were studying the Greek Tragic Poets, he made us read Shakespeare and Milton as lessons: and they were the lessons too, which required most time and trouble to bring up, so as to escape his censure. I learnt from him, that Poetry, even that of the loftiest, and, seemingly, that of the wildest odes, had a logic of its own, as severe as that of science; and more difficult, because more subtle, more complex, and dependent on more, and more fugitive causes. [...] In our own English compositions (at least for the last three years of our school education) he showed no mercy to phrase, metaphor, or image, unsupported by a sound sense, or where the same sense might have been conveyed with equal force and dignity in plainer words... In fancy I can almost hear him now, exclaiming Harp? Harp? Lyre? Pen and ink, boy, you mean! Muse, boy, Muse? your Nurse's daughter, you mean! Pierian spring? Oh aye! the cloister-pump, I suppose! [...] Be this as it may, there was one custom of our master's, which I cannot pass over in silence, because I think it ... worthy of imitation. He would often permit our theme exercises, ... to accumulate, till each lad had four or five to be looked over. Then placing the whole number abreast on his desk, he would ask the writer, why this or that sentence might not have found as appropriate a place under this or that other thesis: and if no satisfying answer could be returned, and two faults of the same kind were found in one exercise, the irrevocable verdict followed, the exercise was torn up, and another on the same subject to be produced, in addition to the tasks of the day.
He later wrote of his loneliness at school in the poem Frost at Midnight: "With unclosed lids, already had I dreamt/Of my sweet birthplace."
From 1791 until 1794, Coleridge attended Jesus College, Cambridge. In 1792, he won the Browne Gold Medal for an ode that he wrote on the slave trade. In December 1793, he left the college and enlisted in the 15th (The King's) Light Dragoons using the false name "Silas Tomkyn Comberbache", perhaps because of debt or because the girl that he loved, Mary Evans, had rejected him. His brothers arranged for his discharge a few months later under the reason of "insanity" and he was readmitted to Jesus College, though he would never receive a degree from the university.