Sir William Mackinnon, 1st Baronet, CIE, FRSGS (23 March 1823 – 22 June 1893) was a Scottish ship-owner and businessman who built up substantial commercial interests in India and East Africa.

The company, founded as a shipping and insurance agency in the City of London, went through several reorganizations and ownership changes, obtaining recognition as a merchant bank in 1915, becoming fully fledged as Gray Dawes Bank in 1973 (sold in 1983), and now known as Gray Dawes Group Ltd.[3][4][5][6] In 1888, Mackinnon founded the Imperial British East Africa Company and became its Chairman.

[1] Mackinnon promoted Henry Morton Stanley's Emin Pasha Relief Expedition, first enlisting Stanley, then writing to government ministers including Lord Iddesleigh, the Foreign Secretary, and enlisting friends to form a committee which could oversee the expedition and meet more than half the cost.

[7] Following the closure of the school, and the sale of the land, the Mackinnon MacNeil Trust was able to continue to help young people and exists now to give bursaries to students from the Western Highlands and Islands going to university.

The papers of Sir William Mackinnon (PP MS 1) are held by Archives and Special Collections at the School of Oriental and African Studies, London.