I was raised in socialist England and Santa Claus was mostly referred to as Father Christmas. Father Christmas is used in many other English speaking countries. A similar figure with the same name (in other languages) exists in several other countries, including France (Père Noël), Spain (Papá Noel), Portugal (Pai Natal), Italy (Babbo Natale), and Romania (Moş Crăciun). In past centuries, the English Father Christmas was also known as Old Father Christmas, Sir Christmas, and Lord Christmas.
Since emigrating to the United States all I hear is Santa and I find most people unfamiliar with Father Christmas.