Mairy-sur-Marne (French pronunciation: [mɛʁi syʁ maʁn], literally Mairy on Marne) is a commune in the Marne department in north-eastern France. The village is situated on the river Marne, which travels through Chalons-en-Champagne, Épernay and on to Paris where it links on to the Seine. In the centre of the village is a church, the mayor's office and the village's 17th century Chateau.^{[citation needed]}

Chateau de Mairy, also known as Chateau de Jaques, is a 'Monument Historique' set on 30 acres of grounds with its own private lake and a pigeonnerie tower which also serves as a chapel.^{[citation needed]}

James II stayed regularly in the Chateau during his exile in France.^{[citation needed]}

It was owned by the Loisson de Guinaumont since it was built in 1676 and was owned by the Count of Guinaumont until 2004 when he died aged 98.^{[citation needed]}

It is now used as a period guest house and hosts travelers, biking groups and charming events such as weddings.^{[citation needed]}