Lazare Marius Arthur Soustre (1 September 1828 – 16 April 1897) was a French lawyer and committed Republican who was imprisoned for his resistance to the coup that brought Napoleon III to power.

[1] His parents were Charles Benoit Soustre (born 1800), an Inspector of Registration and Domains, and Marie Anne-Lazarine Aillaud (1808–1829).

[4] On 10 September 1870 a provisional departmental committee was established in Digne with Charles Cotte, lawyer, as president and Marius Soustre, propriétaire, as secretary.

[4] On 21 August 1881 Soustre ran for election to the National Assembly for the Digne constituency of Basses-Alpes on the Republican Union platform.

He voted for the draft Lisbonne law restricting freedom of the press, and for high court proceedings against General Boulanger.

[6] In September 1900 the French League for the Defense of the Rights of Man and the Citizen decided to launch a public subscription to erect a bust to Marius Soustre.