The 1st constituency of Lot-et-Garonne (French: Première circonscription de Lot-et-Garonne) is a French legislative constituency in the Lot-et-Garonne département.

Like the other 576 French constituencies, it elects one MP using a two round electoral system.

The 1st Constituency of Lot-et-Garonne lies in the south of the département around the small city of Agen on the Garonne river.

Politically the seat had swung between the centre-right Union for French Democracy and the Socialist Party, this changed in 2017 when, along with the other two seats in Lot-et-Garonne it fell to En Marche.

[1] * Withdrew before the 2nd round [3]