Demasson's House and Shop is situated on Stirling Terrace in Toodyay, Western Australia.

By 1875 William Amed Demasson, a carpenter wheelwright from Guildford, Western Australia, had added a dwelling with a connecting door to the store, which was at the time run by his wife.

Land titles show the Toodyay Road Board purchased the dwelling from Amy Twine in 1945.

Mrs O'Reilly was given life-time occupancy of the dwelling after her husband died in 1977; she remained there until at least 1999.

In 2010 the Royalties for Regions programme was able to fund renovation works to the building.