Burns was born two miles (3 km) south of Ayr, in Alloway, Ayrshire, Scotland, the eldest of the seven children of William Burnes (1721–1784) (Robert Burns spelled his surname Burnes until 1786), a self-educated tenant farmer from Dunnottar, The Mearns, and Agnes Broun (or Brown) (1732–1820), the daughter of a tenant farmer from Kirkoswald, Ayrshire.
He was born in a house built by his father (now the Burns Cottage Museum), where he lived until Easter 1766, when he was seven years old. William Burnes sold the house and took the tenancy of the 70-acre (280,000 m2) Mount Oliphant farm, southeast of Alloway. Here Burns grew up in poverty and hardship, and the severe manual labour of the farm left its traces in a premature stoop and a weakened constitution.
He had little regular schooling and got much of his education from his father, who taught his children reading, writing, arithmetic, geography, and history and also wrote for them A Manual Of Christian Belief. He was also taught by John Murdoch (1747–1824), who opened an "adventure school" in Alloway in 1763 and taught Latin, French, and mathematics to both Robert and his brother Gilbert (1760–1827) from 1765 to 1768 until Murdoch left the parish. After a few years of home education, Burns was sent to Dalrymple Parish School during the summer of 1772 before returning at harvest time to full-time farm labouring until 1773, when he was sent to lodge with Murdoch for three weeks to study grammar, French, and Latin.
By the age of 15, Burns was the principal labourer at Mount Oliphant. During the harvest of 1774, he was assisted by Nelly Kilpatrick (1759–1820), who inspired his first attempt at poetry, "O, Once I Lov'd A Bonnie Lass". In the summer of 1775, he was sent to finish his education with a tutor at Kirkoswald, where he met Peggy Thompson (b.1762), to whom he wrote two songs, "Now Westlin' Winds" and "I Dream'd I Lay".
Despite his ability and character, William Burnes was consistently unfortunate, and migrated with his large family from farm to farm without ever being able to improve his circumstances. At Whitsun, 1777, he removed his large family from the unfavourable conditions of Mount Oliphant to the 130-acre (0.53 km2) farm at Lochlea, near Tarbolton, where they stayed until William Burnes' death in 1784. Subsequently, the family became integrated into the community of Tarbolton. To his father's disapproval, Robert joined a country dancing school in 1779 and, with Gilbert, formed the Tarbolton Bachelors' Club the following year. His earliest existing letters date from this time, when he began making romantic overtures to Alison Begbie (b. 1762). In spite of four songs written for her and a suggestion that he was willing to marry her, she rejected him.
Robert Burns was initiated into masonic Lodge St David, Tarbolton, on 4 July 1781, when he was 22.
In December 1781, Burns moved temporarily to Irvine, Ayrshire, to learn to become a flax-dresser, but during the workers' celebrations for New Year 1781/1782 (which included Burns as a participant) the flax shop caught fire and was burnt to the ground. This venture accordingly came to an end, and Burns went home to Lochlea farm. During this time he met and befriended Captain Richard Brown who encouraged him to become a poet.
He continued to write poems and songs and began a commonplace book in 1783, while his father fought a legal dispute with his landlord. The case went to the Court of Session, and Burnes was upheld in January 1784, a fortnight before he died.
Robert and Gilbert made an ineffectual struggle to keep on the farm, but after its failure they moved to the farm at Mossgiel, near Mauchline, in March, which they maintained with an uphill fight for the next four years. During the summer of 1784 Burns came to know a group of girls known collectively as The Belles of Mauchline, one of whom was Jean Armour, the daughter of a stonemason from Mauchline.
His first child, Elizabeth Paton Burns (1785–1817), was born to his mother's servant, Elizabeth Paton (1760–circa 1799), while he was embarking on a relationship with Jean Armour, who became pregnant with twins in March 1786. Burns signed a paper attesting his marriage to Jean, but her father "was in the greatest distress, and fainted away". To avoid disgrace, her parents sent her to live with her uncle in Paisley. Although Armour's father initially forbade it, they were eventually married in 1788. Armour bore him nine children, only three of whom survived infancy.
Burns was in financial difficulties due to his want of success in farming, and to make enough money to support a family he took up a friend's offer of work in Jamaica, at a salary of £30 per annum. The position that Burns accepted was as a bookkeeper on a slave plantation. Burns's egalitarian views were typified by "The Slave's Lament" six years later, but in 1786 there was little public awareness of the abolitionist movement that began about that time.
At about the same time, Burns fell in love with Mary Campbell (1763–1786), whom he had seen in church while he was still living in Tarbolton. She was born near Dunoon and had lived in Campbeltown before moving to work in Ayrshire. He dedicated the poems "The Highland Lassie O", "Highland Mary", and "To Mary in Heaven" to her. His song "Will ye go to the Indies, my Mary, And leave auld Scotia's shore?" suggests that they planned to emigrate to Jamaica together. Their relationship has been the subject of much conjecture, and it has been suggested that on 14 May 1786 they exchanged Bibles and plighted their troth over the Water of Fail in a traditional form of marriage. Soon afterwards Mary Campbell left her work in Ayrshire, went to the seaport of Greenock, and sailed home to her parents in Campbeltown.
In October 1786, Mary and her father sailed from Campbeltown to visit her brother in Greenock. Her brother fell ill with typhus, which she also caught while nursing him. She died of typhus on 20 or 21 October 1786 and was buried there.
As Burns lacked the funds to pay for his passage to the West Indies, Gavin Hamilton suggested that he should "publish his poems in the mean time by subscription, as a likely way of getting a little money to provide him more liberally in necessaries for Jamaica." On 3 April Burns sent proposals for publishing his Scotch Poems to John Wilson, a local printer in Kilmarnock, who published these proposals on 14 April 1786, on the same day that Jean Armour's father tore up the paper in which Burns attested his marriage to Jean. To obtain a certificate that he was a free bachelor, Burns agreed on 25 June to stand for rebuke in the Mauchline kirk for three Sundays. He transferred his share in Mossgiel farm to his brother Gilbert on 22 July, and on 30 July wrote to tell his friend John Richmond that, "Armour has got a warrant to throw me in jail until I can find a warrant for an enormous sum ... I am wandering from one friend's house to another."
On 31 July 1786 John Wilson published the volume of works by Robert Burns, Poems, Chiefly in the Scottish dialect. Known as the Kilmarnock volume, it sold for 3 shillings and contained much of his best writing, including "The Twa Dogs", "Address to the Deil", "Halloween", "The Cotter's Saturday Night", "To a Mouse", "Epitaph for James Smith", and "To a Mountain Daisy", many of which had been written at Mossgiel farm. The success of the work was immediate, and soon he was known across the country.
Burns postponed his planned emigration to Jamaica on 1 September, and was at Mossgiel two days later when he learnt that Jean Armour had given birth to twins. On 4 September Thomas Blacklock wrote a letter expressing admiration for the poetry in the Kilmarnock volume, and suggesting an enlarged second edition. A copy of it was passed to Burns, who later recalled, "I had taken the last farewell of my few friends, my chest was on the road to Greenock; I had composed the last song I should ever measure in Scotland – 'The Gloomy night is gathering fast' – when a letter from Dr Blacklock to a friend of mine overthrew all my schemes, by opening new prospects to my poetic ambition. The Doctor belonged to a set of critics for whose applause I had not dared to hope. His opinion that I would meet with encouragement in Edinburgh for a second edition, fired me so much, that away I posted for that city, without a single acquaintance, or a single letter of introduction."