SAO biscuits are a savoury cracker biscuit that was launched in Australia in 1904 by Arnott's, the term SAO being trade marked in 1904.

A widely held belief is that the name is an acronym for "Salvation Army Officer", and was named for Arthur, one of the Arnott brothers, who was indeed an officer in the Salvation Army.

The Salvation Army Australia somewhat cautiously mentions this on its website, calling it "Arguably Fact" and saying "...it is understood they named it in honour of their brother Arthur Arnott, a Salvation Army Officer.

"[7] SAOs are often eaten as a light snack, topped with butter/margarine and Vegemite, or other ingredients.

[8] They were also a common base for home-made vanilla slice in Australian homes.