Nathan “Natie” Kirsh was born in South Africa on 6 January 1932, and grew up in a Jewish family in Potchefstroom, where he matriculated from Potchefstroom Boys High, in 1949. Kirsh earned a Bachelor of Commerce at the University of the Witwatersrand, in 1952. He also holds an honorary doctorate from the University of Swaziland.

In 1952, Kirsh began assisting his mother with the operation of his father’s original malt factory in Potchefstroom, then, in 1958, launched his own first venture, founding a corn milling and malt business in Eswatini.

After having returned to South Africa, in 1968; in 1970, Kirsh acquired Moshal Gevisser, a South African wholesale food distributor with a pilot cash and carry program. At the time, the South African apartheid government prevented white business-owners from operating in black townships, and Kirsh began using Moshal Gevisser to supply goods to black shopkeepers. As a cash and carry business, Moshal Gevisser became a dominant food retailer in South Africa.

In June 1976, he founded Jetro, a cash and carry store in Brooklyn, New York. He acquired Restaurant Depot in 1994, then opened its first New York retail outlet in 1995, and Jetro and Restaurant Depot began operating as sister businesses under Jetro Holdings. In 2003, Warren Buffett agreed to buy a minority share of Jetro Holdings, however, he and Kirsh could not agree on terms. As of August 2018, Kirsh owned 75 percent of Jetro Holdings, which had about 115 Jetro Cash & Carry and Restaurant Depot stores in the United States. That year, the Independent reported that several of Kirsh’s companies were registered in the British Virgin Islands and in Liberia, both of which are listed on the Organisation for Economic Co-operation and Development’s tax haven “grey list”. Kirsh Holdings Group, Kirsh’s primary holding group, continues to own half of Swazi Plaza Properties.

Kirsh left South Africa in 1986, after selling much of Kirsh Industries to Sanlam, In 2006, his companies included Mira Mag and Ki Corporation. Through Kifin Limited, part of Ki Corporation, by 2008, he also held a stake in Minerva, dropping a bid for majority ownership in 2010.

In the late 1970s, he also acquired Magal Security Systems from Israel Aerospace Industries, listing the company on Nasdaq in 1993. In 2009, Kirsh was a director and held a 24.2 percent stake in Magal Security, which met controversy by providing fences in Israel. In 2014, Kirsh sold his 40 percent stake in Magal to FIMI.

By early 2018, Kirsh retained retail and property interests in Britain, the United States, Australia, and Swaziland. Bloomberg estimated his wealth at USD $6.09 billion in March 2019, and ranked him as #267 on its international “Bloomberg Billionaire’s Index”. He also appeared on the Sunday Times Rich List 2018 as the 31st richest person in the United Kingdom, with a reported fortune of £3.9 billion. and was named as the wealthiest person in Swaziland for 2019 by Forbes. Kirsh was ranked the 614th-richest person in the world on the Forbes list of The World’s Billionaires for 2020, with a fortune reported as US$4 billion.