Jean Dionis du Séjour (French pronunciation: [ʒɑ̃ djɔnis dy seʒuʁ]; born 21 September 1956), also known as Jean Dionis, is a French politician who has served as Mayor of Agen since 2008.

[1] He represented the 1st constituency of the Lot-et-Garonne department in the National Assembly from 2002 to 2012.

He retained a seat in the municipal council of Agen until his resignation in 2004.

[2] He served as the deputy in the National Assembly for the 1st constituency of the Lot-et-Garonne department from 2002 to 2012.

[4] He lost his parliamentary seat at the 2012 legislative election, which he unsuccessfully tried to regain at the 2017 election under the Union of Democrats and Independents (UDI) banner with the support of The Republicans (LR),[5] when he was defeated in the second round by Michel Lauzzana of La République En Marche!