William Leiper was born in Glasgow on 21 May 1839, the son of William Leiper who and Jane Mellis. Educated by his father and at Glasgow High School, he served his apprenticeship with Boucher & Cousland from '1855-6' to about 1859 when he went to London, working for John Loughborough Pearson and William White for approximately one year each.
It was in London that he gained an entrée to the circle of Edward William Godwin and William Burges, who was later to propose him as FRIBA. Upon returning from a stint in Dublin he found a place with Campbell Douglas & Stevenson in Glasgow. By early 1864 he had formed a partnership with Robert Grieve Melvin which ended in dispute.
Leiper's reputation was immediately established by winning the competition for Dowanhill Church, Glasgow in 1864. The following year Leiper designed both Dumbarton Academy and Burgh hall. In some of his less expensive early houses he adopted the low-pitched roofs and compositional methods of Alexander Thomson, a friend in his early years, notably at Bonnington (now Rhuarden), Helensburgh, Dumbartonshire, and Castlepark, Lanark.
A long series of churches and mansions followed, all more or less influenced by the Gothic revival. Specimens of his churches are to be seen at Whiteinch, Camphill, Lanark, and Brechin. Then in the style of François Premier came Partick Burgh Hall and the mansions of the Elms, Arbroath, Cairndhu, Helensburgh, and Cornhill, Lanarkshire. In the seventies came the influence of the Scottish Baronial or Domestic style of the seventeenth century, and examples are Colearn and Ruthven Tower at Auchterarder, Dalmore at Helensburgh, and the unexecuted design for Earnock, in Lanarkshire.
About this time he designed the palace portions of the Czar's famous yacht Livadia. In the following years he designed among other houses Kinloch Moidart, in Inverness-shire, Moredun at Paisley, and Kelly House at Wemyss Bay; and among his later churches may be cited Hyndlands, based upon the style of the early Scottish churches.
More recent specimens of his work are to be seen in the Venetian Gothic of Messrs. Templeton's carpet factory at Glasgow Green, of red brick, terra cotta, and coloured Mosaic, and the renaissance block of offices for the Sun Insurance Company at the corner of Renfield Street and West George Street. A silver medal was awarded Mr. Leiper for this design at the Paris International Exhibition of 1900. Ruyton Park, Shropshire, and Langarth, Stirling, are examples of his work.
The William Black Memorial, near Oban, was erected from his designs. Examples of his art work are also to be seen in the stained glass of several of his churches. The designing of the decoration of the Banqueting Hall in the Municipal Chambers was entrusted to him, and was carried out under his direction. His most recent architectural work has been the designing of the mansion of Ballimore, Loch Fyne, the mansion of Glendaruel, and the new church of St. James, Kilmacolm.
Mr. Leiper was elected Fellow of the Royal Institute of British Architects in 1881, Associate of the Royal Scottish Academy ten years later, and Royal Scottish Academician in 1896. From 1870 onward he exhibited works in watercolour and oil as well as architecture.
Leiper never married. After a protracted illness which resulted from serious blood poisoning in 1903, Leiper was compelled to retire completely in 1909 and his practice was continued by his partner William Hunter McNab, an accomplished designer in the same idiom.
Leiper died of a cardiac haemorrhage at Helensburgh on 27 May 1916. He left moveable estate of £6,535 10s 4d