The 39th Infantry Regiment (French: 39e régiment d'infanterie (39e RI)) was a line infantry regiment of the French Army.

It was renamed the régiment d’Isle-de-France in 1762 then the 39th Line Infantry Regiment in 1791.

It was renamed a demi-brigade in 1793 but retained the numeral 39.

It resumed its 1791 title in 1803, before being renamed the Légion de la Seine inférieure (1815), then the 1re légion de la Seine inférieure (1819).

This article about a specific French military unit is a stub.