He was born in Kirriemuir, Forfarshire to Janet Thomson, an unmarried girl. Janet declined to marry Alexander's father, John Whyte, who thereafter went to America. She did however give Alexander his father's surname. His mother joined the Free Church of Scotland at the Disruption of 1843. In 1848 he began an apprenticeship as a cobbler. In 1854 he took on a role as schoolteacher at Padanarum in Forfar and the following year moved to teach in Airlie. In Airlie the local minister taught him Latin and Greek, enabling him to apply for university
He studied divinity at the University of Aberdeen and then at New College, Edinburgh graduating in 1866. This was in part funded by his estranged father. His half-sister, Elizabeth Whyte, came to join him from America to help him keep house. There she met his colleague, Rev Thomas Macadam, whom she married.
Alexander entered the ministry of the Free Church of Scotland and after serving as colleague in Free St John's, Glasgow (1866–1870), removed to Edinburgh as colleague and successor to Rev Dr Robert Candlish at Free St George's. In 1909 he succeeded Dr Marcus Dods as principal, and professor of New Testament literature, at New College, Edinburgh.
Whyte lived in a huge townhouse 7 Charlotte Square, in Edinburgh's First New Town. The house is now owned by the National Trust for Scotland and open to the public as The Georgian House, Edinburgh.
In 1881 he was married to Jane Elizabeth Barbour (1861-1944). Their son Robert Barbour Whyte was killed in the First World War.
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- One or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Whyte, Alexander". Encyclopædia Britannica. 28 (11th ed.). Cambridge University Press. p. 617.
- Edinburgh and Leith Post Office Directory 1889-90
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- "Eminent Edinburgh Citizens. Two New Burgesses. An Interesting Ceremony". The Glasgow Herald. 11 December 1909. p. 10. Retrieved 25 February 2018.
- Macaulay, A. B.; Matthew, H. C. G. "Whyte, Alexander (1836–1921)". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/36886.(Subscription or UK public library membership required.)
- G.F. Barbour. The life of Alexander Whyte. Hodder & Stoughton. London 1923. OCLC 1652290