As Australian* as the Sydney Opera House or the Harbour Bridge. A thick dark spread used on toast or bread, or flavouring in soups and casseroles, and loved by Aussies since the early 1920s.
This Australian icon was developed in 1922 by Australian food technologist, Cyril P Callister, and marketed by a Melbourne businessman, Fred Walker. Made from the yeast left-overs of the beer making process, it became one of the positive side effects of the Australian brewing industry of the 1920s.
Vegemite's reputation for nutrition was boosted when infant welfare centres recommended its use for toddlers to receive their quota of vitamins B1, B2 and Niacin, but the manufacturers failed to mention that it also contained 10% salt, and so in its early days it was marketed as 'health' food. It has since had its salt levels reduced, so it conforms to health considerations.
(* Vegemite is made in Australia by Kraft Foods. In 1988 Kraft Inc was acquired by Philip Morris Companies Inc. So whilst it is manufactured by an American owned company, it is recognised as an Australian icon.)