RIOM a town of France, with 9590 inhabitants, at the head of an arrondissement in the department of Puy-de-Dôme, 8 miles north of Clermont-Ferrand on the railway to Paris, occupies an eminence on the left bank of the Ambène (a left-hand tributary of the Allier) rising above the fertile plain of Limagne. It is surrounded with boulevards and has wide streets, but the houses, being built of black lava, have a rather sombre appearance. Some date from the 15th and 16th centuries, with turrets and ancient carved work. The church of St Amable goes back to the 12th century, but has suffered by repeated restorations. The old ducal palace (now occupied by the court of appeal, etc.) has a collection of portraits of Auvergne celebrities. A feature in the town is the fountains, of which some are of the Renaissance period. Riom trades in the products of Limagne—grain, wine, hemp, preserved fruits, and especially a conserve of apricots—and has a tobacco manufactory.

Riom {Rieomagus or Rieomum of the Romans) was long the rival of Clermont. Along with Auvergne it was seized for the crown by Philip Augustus, and it was the capital of this province under the dukes of Berri and Bourbon. During the religious wars it long held with the League. Its courts of law, always famous, are associated with the memory of D’Aguesseau.