Peter Bayne (1830–1896) was a Scottish author.
He was the second son of Charles John Bayne (died 11 Oct. 1832), minister of Fodderty, Ross-shire, Scotland, and his wife Isabella Jane Duguid. He was born at the manse, Fodderty, on 19 October 1830. He was educated at Inverness academy, Aberdeen grammar school, Bellevue academy, and Marischal College, Aberdeen, where he took the degree of M.A. in 1850. While an undergraduate at Aberdeen he won the prize for an English poem, and in 1854 was awarded the Blackwell prize for a prose essay. 
From Aberdeen he proceeded to Edinburgh, and entered the theological classes at New College in preparation for the ministry. But bronchial weakness and asthma made preaching an impossibility, and he turned to journalistic and literary work as a profession. He began as early as 1850 to write for Edinburgh magazines, and in the years that followed much of his work appeared in Hogg's Weekly Magazine and Tait's Edinburgh Magazine. He was for a short time editor of the Glasgow Commonwealth, and in 1806, on the death of his friend, Hugh Miller, whose life he wrote, succeeded him in Edinburgh as editor of the Witness. A visit to Germany to acquire a knowledge of German led to his marriage in 1858 to Clotilda, daughter of General J. P. Gerwien. 
Up to this point his career had been uniformly successful, and his collected essays had brought him reputation not only in Scotland but in America; but in 1860 he took up the post of editor of the Dial, a weekly newspaper planned by the National Newspaper League Company on an ambitious scale in London. The Dial proved a financial failure. Bayne not only struggled heroically to save the situation by editorial ability, but he lost all his own property in the venture, and burdened himself with debts that crippled him for many years. In April 1862, he retired from the Dial, and became editor of the Weekly Review, the organ of the English presbyterian church. This he resigned in 1865, because his views on inspiration were held to be unsound, and be declined any further editorial responsibilities. 
But he became a regular leader writer for the Christian World, under the editorship of James Clarke. For more than twenty years his peculiar combination of broad-minded progressive liberalism with earnest and eager evangelicalism gave a distinct colour to the religious, social, political, and literary teaching of this influential paper. He found here the main work of his life; but wrote independently much on the history of England in the seventeenth century, many essays in literary criticism, and a biography of Martin Luther. He also contributed occasionally to the Nonconformist, the Spectator, and other weekly papers, as well as to the leading reviews, notably the Contemporary Review, the Fortnightly, the British Quarterly, the London Quarterly, and Fraser's Magazine. 
In 1879, the degree of LL.D. was conferred on him by Aberdeen University. He died at Norwood on 10 February 1896, and is buried in Harlington churchyard, Middlesex, where he resided during the earlier half of his London career. 
He was thrice married, but had issue only by his first wife, who died in childbirth in 1865, leaving him with three sons and two daughters. His second wife, Anna Katharine, daughter of Herbert Mayo of Oakhill, Hampstead, whom he married in 1869, died in 1882 after a life of devotion to the welfare of his children. His third wife became insane towards the end of 1895, and grief on this account contributed to his own death.
Besides many uncollected magazine articles, several pamphlets, and part of the fourth volume of the National History of England (1877), Bayne's chief works are:
- The Christian Life, Social and Individual, Edinburgh, 1855, 8vo; Boston, 1857; new edit. London, 1859.
- Essays, Biographical, Critical, and Miscellaneous, Edinburgh, 1859, 8vo. These were also published in Boston, Massachusetts, in two volumes.
- The Testimony of Christ to Christianity, London, 1862, 8vo.
- Life and Letters of Hugh Miller, London, 1871, 2 vols. 8vo.
- The Days of Jezebel: an historical drama, London, 1872, 8vo.
- Emma Cheyne: a Prose Idyll of English Life, 1875 (published under the pseudonym of Ellis Brandt).
- The Chief Actors in the Puritan Revolution, London, 1878, 8vo.
- Lessons from my Masters — Carlyle, Tennyson, and Ruskin, London, 1879, 8vo.
- Two Great Englishwomen: Mrs. Browning and Charlotte Bronte, with an Essay on Poetry, London, 1881, 8vo.
- Martin Luther: his Life and Work, London, 1887, 8vo.
- The Free Church of Scotland: her Origin, Founders, and Testimony, Edinburgh, 1893 ; 2nd edit. 1894. 
This article incorporates text from a publication now in the public domain: Bayne, Ronald (1901). "Bayne, Peter". In Sidney Lee. Dictionary of National Biography, 1901 supplement. London: Smith, Elder & Co.