Gallia Lugdunensis (French: Gaule Lyonnaise) is a province of the Roman Empire in what is now the modern country of France, part of the Celtic territory of Gaul formerly known as Celtica.

It is named after its capital Lugdunum (today's Lyon), possibly Roman Europe's major city west of Italy, and a major imperial mint.

Outside Lugdunum is the Condate Altar, where representatives of the Three Gauls meet to celebrate the cult of Rome and Augustus.In De Bello Gallico describing his conquest of Gaul (58-50 BCE), Julius Caesar distinguished between provincia nostra in the south of Gaul, which already was a Roman province in his time, and the three other parts of Gaul: the territories of the Aquitani, of the Belgae, and of the Galli also known as the Celtae.

The territory of the Galli extends from the rivers Seine and Marne in the northeast, which forms the boundary with Gallia Belgica, to the river Garonne in the southwest, which forms the border with Gallia Aquitania.

Under Augustus, Gallia Lugdunensis is created by reducing in size the territory of the Galli: The portion between the river Loire and the Garonne is given to Gallia Aquitania, and central-eastern portions are given to the new province of Germania Superior.

The map shows the extent after these reductions.

The date of the creation of Gallia Lugdunensis is under discussion, whether between 27-25 BCE or between 16-13 BCE, during Augustus' visits to Gaul.It is an imperial province, deemed important enough to be governed by an imperial legate.

After Diocletian's Tetrarchy (CE 296), it is the major province of a diocese confusingly called Galliae ('the Gaul provinces'), to which further only the Helvetic, Belgian (both also Celtic) and German provinces belong; with the dioceses of Viennensis (the southern provinces of Gaul), Britanniae (also Celtic) and Hispaniae (the whole Celtiberian peninsula) this forms the praetorian prefecture also called Galliae, subordinate to the western emperor.The province effectively ceases to exist in 486 when the Roman general Syagrius is defeated by the invading Franks.