Events from the year 1790 in Scotland.

• 16 June–28 July – British general election gives Pitt an increased majority.^[1]
• 28 June – Forth and Clyde Canal opened.^[1]
• October – Pladda Lighthouse first illuminated.^[2]
• Balblair distillery at Edderton founded.
• Caerlee Mill at Innerleithen completed, the oldest woollen mill in the Scottish Borders.
• New Ardkinglas Castle built.
• Construction of Gosford House to the design of Robert Adam for Francis Wemyss-Charteris is begun.
• The mineral element strontium is discovered near Strontian by chemists Adair Crawford and William Cruickshank.
• Approximate date – Whaligoe steps cut.

• 3 March – Robert Story, Church of Scotland minister and writer (died 1859)
• 25 October – Robert Stirling, Church of Scotland minister and inventor of the Stirling engine (died 1878)
• 29 October – David Napier, marine engineer (died 1869 in London)
• James Clow, Presbyterian minister and settler in Melbourne (died 1861 in Australia)
• Approximate date – Mary Diana Dods, writer as "David Lyndsay", later known as "Walter Sholto Douglas" (died 1830 in France)

• 5 February – William Cullen, physician and chemist (born 1710)^[3]
• 4 March – Flora MacDonald, Jacobite (born 1722)
• 17 July – Adam Smith, economist and philosopher (born 1723)
• 24 November – Robert Henry, historian and Church of Scotland minister (born 1718)^[4]

• Catholic priest Alexander Geddes writes the poem Linton: a Tweedside Pastoral, Carmen Seculare pro Gallica Gente in praise of the French Revolution.
• Kirkmichael musician Robert Petrie publishes several Highland music pieces with "Mrs. Small of Dirnanean" in their title. The compositions are published in "Petrie's Collection of Strathspey Reels & County Dances".^[5]