The Celtic culture had its origins in the central European Hallstatt culture (c. 800–450 BCE), named for the rich grave finds in Hallstatt, Austria. By the later La Tène period (c. 450 BCE up to the Roman conquest), this Celtic culture had, whether by diffusion or migration, expanded over a wide range, including into the southern area of the Netherlands. This would have been the northern reach of the Gauls.

Scholars debate the actual extent of the Celtic influence. The Celtic influence and contacts between Gaulish and early Germanic culture along the Rhine is assumed to be the source of a number of Celtic loanwords in Proto-Germanic. But according to Belgian linguist Luc van Durme, toponymic evidence of a former Celtic presence in the Low Countries is near to utterly absent. Although there were Celts in the Netherlands, Iron Age innovations did not involve substantial Celtic intrusions and featured a local development from Bronze Age culture.