Robert P. Whitelaw, mechanical and construction engineer, was the son of Robert Whitelaw, an iron moulder, and his wife Janice White. He was educated at the West of Scotland Technical College at Coatbridge, near Glasgow. Shortly before the Anglo-Boer War (1899-1902) he came to South Africa, working in Johannesburg as engineer and contractor. In May 1898 he became a foundation member and was elected on the first council of the Mechanical Engineers' Association of the Witwatersrand. His paper on "Compressed air" was the first to be read before the association. In 1903 he became a member also of the Chemical, Metallurgical and Mining Society of South Africa. In 1906 he applied for a license to peg 50 claims on the farm Rondebult No. 152 (south-east of Fochville). A wider interest in scientific matters is shown by his letter to the government of the Transvaal Colony in 1904, about injurious insects. He resided in Johannesburg to at least 1911, in which year he applied to rent the farm Zoutpan, No. 174.
Following the outbreak of World War I (1914-1918) Whitelaw went to England in 1915 at the request of the British Ministry of Munitions and was put in charge of the large scale manufacture of mustard gas. In 1920 he was honoured as a Commander of the Order of the British Empire (CBE). He later returned to South Africa and settled on Prairie Bird Farm, near Bloemhof.
Whitelaw was married to Helen Watson, with whom he had four sons. He later married Elizabeth H.M. Palmer.