Yes, it is a Victorian cufflink; I think it is too large to be a shirt stud. Before 1870, cufflinks were 2 pieces held together with generally a chain or a link. During the 1880's George Krementz patented a device based on a
civil war cartridge shell-making machine that could mass produce one-piece
collar buttons and cufflinks. Your cufflink looks to be circa 1880-1900.