The Victorian Era specifically refers to the period of Queen Victoria’s extremely long reign (1837-1901), and in this sense it is correct to use a narrow definition: that which was happening in England and the rest of the United Kingdom at that time. The High and Late Victorian Eras correspond with the Belle Epoque in Continental Europe and the Gilded Age in the United States.
In modern usage, however, “Victorian” is often applied to describe all the happenings of that time, whether within the UK or without. With respect to antiques, it is now common to call antiques of the Era “Victorian”, regardless of the actual place of manufacture.