The family immigrated to Australia in 1926, settling in Perth where his father opened a butcher's shop on Barrack Street.
The company became "one of Western Australia’s biggest meat-processing firms",[1] exporting sausages and smallgoods overseas to Singapore and the Dutch East Indies.
[4] In October 1964 he announced that his firm had become insolvent, stating in a notice to creditors that "the stock and receivables of the company had been gravely overvalued".
[6] In 1954 he publicly criticised federal opposition leader H. V. Evatt's statements on the Commonwealth Court of Conciliation and Arbitration.
In the lead-up to the 1947 Western Australian state election he "took a leading role in mobilising business support in the campaign".
[1] Johnston was elected state president of Liberal and Country League in 1954,[1] but resigned in February 1955 to take an overseas trip.