The division is located in the eastern suburbs of Melbourne, coextensive with the City of Knox local government area.

The suburbs in the division include Bayswater, Boronia, Ferntree Gully, Knoxfield, Rowville, Scoresby, The Basin, Wantirna and Wantirna South; and parts of Lysterfield, Sassafras and Upper Ferntree Gully.

[1] The division was created in 1984 and is named after Tilly Aston, a blind writer and teacher who helped found the Library of the Victorian Association of Braille Writers in 1894.

At the 2022 Australian federal election it was the Liberal Party’s safest seat in metropolitan Melbourne.

[3] Aston has one of the biggest Chinese-Australian communities in Victoria, with more than 22,500 Chinese residents, or about 14 per cent of the electorate's population.