It is not known accurately the true etymological meaning of Portugalete, so there are several theories that attempt to explain the origin of this name. For some experts, the equivalent in latin could be "Portus Gallorum" which means "gauls’ port", while according to others, Portugalete would mean "galley port".

On the other hand, some people argue that the name of the place would be "Ugalete" which in Basque language could mean "cornerback place of water "and that it will be preferred by the Latin word "Portu". Another theory affirms that Portugalete would mean "pebbles port", based on the French word "galet" that means "pebble".