A style of decorative art, widely regarded as one of the most impressive known from antiquity that developed around 500 bc in central and western Europe and found expression in the following centuries over a wide area from Spain and Ireland across to eastern Germany. Also known in its early stages as La Tène art. The development of the style in the 5th century bc owes much to the artistic genius of local craftsmen building on the tradition of Hallstatt, Gmunden, Austria geometric and abstract art, coupled with influences resulting from material introduced through trade, especially the animal designs seen on Scythians artefacts from the steppes of eastern Europe and the plant motifs found in the classical world. The result of this combination was a bold curvilinear style with a fascinating blurring of the distinction between naturalistic and abstract with a strong sense of balance but not of symmetry. Such art is applied extensively on bronzework, horse-gear, weapons, and eating and drinking equipment. There are also notable examples carved in stone. A series of stages to the development of Celtic art was suggested by Paul Jacobsthal in 1944: successively, the Early; Waldalgesheim; Plastic; and Sword styles.

The Celtic art styles of the later 1st millennium bc continued to flourish in the northern and western extremes of its early distribution, outside the direct influence of the Roman empire: for example, southern Scandinavia, Ireland, and the west of Britain. Indeed, the styles and ideas survived to return after the Roman withdrawal, fertilizing the artistic revivals of Anglo-Saxon, Norse, and British art from the 5th century ad onwards.