Auguste André Coussillan (31 July 1886 – 15 April 1984) was a French historian specialising in the history of Paris.

Hillairet also began his career in the public sector and was employed at the telephone exchange on rue de Grenelle in 1910.

He organised conference tours on old Paris and changed his name to carry out this activity so that, in his words, "his little comrades in the army would not mess with him”.

He also directed the Évocation du Grand Paris series, which includes three works by the historian Georges Poisson.

[5] In 1957, he received the literary grand prize from the General Council of the Seine and, in 1978, the vermeil medal from the City of Paris.