Fonthill Splendens was a country mansion in Wiltshire, built by Alderman William Beckford; building began in 1755 and was largely complete by 1770. The construction followed the destruction by fire of the previous Fonthill House. The new mansion had a life of only fifty years, being demolished in 1807. As with the earlier building, the mansion was in its time just known as Fonthill House. The name Fonthill Splendens may have been used colloquially but only appeared in print in 1829, some twenty years after the house was demolished.