Reid-Daly, who was born in Salisbury, then capital of the British colony of Southern Rhodesia, entered military service in 1951 and served with the all-Rhodesian "C" Squadron of the Special Air Service (SAS) in counter-insurgency operations in Malaya. He rose to the rank of Regimental Sergeant Major in the Rhodesian Light Infantry and was later commissioned and achieved the rank of Captain. He retired from the Army in 1971.
In late 1971 he was persuaded by General Peter Walls, then chief of the Rhodesian Army, to return to active duty in order to form the Selous Scouts, an elite special forces unit to combat the growing threat posed by nationalist guerrillas. Drawing on his Malayan experience, Lieutenant Colonel Reid-Daly built a skilled and highly professional regiment from scratch. Although the Selous Scouts achieved many of their military objectives, their unorthodox methods created tensions within the military hierarchy. Reid-Daly had several brushes with the Rhodesian authorities.
In 1979 rumours surfaced in Salisbury that the Scouts were poaching ivory along the Zambezi valley. These rumours were never proved, and the colonel, as a well-known conservationist, dismissed the allegations as ridiculous. In the process of defending himself against them, Reid-Daly verbally attacked Major General John Hickman. For this he was charged with insubordination and sentenced to a reprimand. Disgusted, he resigned as the commander of the Scouts in August but continued to fight a legal battle against the judgement, proclaiming his innocence even after Rhodesia descended into Zimbabwe- and only stopped doing so after he was forced to flee to South Africa in 1982.
In South Africa, Reid-Daly became commander of the Transkei Defence Force, and he was subsequently the leader of the private security firm Security Services Transkei Pty Ltd. For the final decade of his life, he resided near Cape Town.
- Selous Scouts: Top Secret War. Galago Publishing. 1982. ISBN 978-0-620-05771-4.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles> with Peter Stiff
- Staying alive: a Southern African survival handbook. Ashanti. 1990. ISBN 978-1-874800-09-5.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- 'Pamwe Chete: The Legend of the Selous Scouts. Covos-Day. 1999. ISBN 978-0-620-23756-7.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Beckett, Ian F.W. (2004). Modern Insurgencies and Counter-Insurgencies: Guerrillas and their Opponents since 1750. Routledge. ISBN 978-1-134-55394-5.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- "Lieutenant-Colonel Ron Reid-Daly". The Telegraph. 20 September 2010. Retrieved 2015-08-28.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>