The La Tène culture was a European Iron Age culture. It developed and flourished during the late Iron Age (from about 450 BCE to the Roman conquest in the 1st century BCE), succeeding the early Iron Age Hallstatt culture without any definite cultural break, under considerable Mediterranean influence from the Greeks in pre-Roman Gaul, the Etruscans, and the Golasecca culture, but whose artistic style nevertheless did not depend on those Mediterranean influences.

La Tène culture's territorial extent corresponded to what is now France, Belgium, Switzerland, Austria, England, Southern Germany, the Czech Republic, parts of Northern Italy and Central Italy, Slovenia and Hungary, as well as adjacent parts of the Netherlands, Slovakia, Serbia, Croatia, Transylvania (western Romania), and Transcarpathia (western Ukraine). The Celtiberians of western Iberia shared many aspects of the culture, though not generally the artistic style. To the north extended the contemporary Pre-Roman Iron Age of Northern Europe, including the Jastorf culture of Northern Germany and all the way to Galatia in Asia Minor (today Turkey).

Centered on ancient Gaul, the culture became very widespread, and encompasses a wide variety of local differences. It is often distinguished from earlier and neighbouring cultures mainly by the La Tène style of Celtic art, characterized by curving "swirly" decoration, especially of metalwork.

It is named after the type site of La Tène on the north side of Lake Neuchâtel in Switzerland, where thousands of objects had been deposited in the lake, as was discovered after the water level dropped in 1857. La Tène is the type site and the term archaeologists use for the later period of the culture and art of the ancient Celts, a term that is firmly entrenched in the popular understanding, but presents numerous problems for historians and archaeologists.