In the six weeks to 7 January, sales growth in the UK was 11.6 per cent, which the company said was "driven by like-for-like growth and e-commerce".
After opening up a raft of new stores and concessions abroad, international sales jumped 69.4 per cent. Reiss now has stores in 17 countries. In total, Reiss opened 28 stores last year.
In April last year, U.S. private equity firm Warburg Pincus took a majority stake in Reiss in a deal that valued the upmarket fashion chain at £230m. The partnership has been helping Reiss to become a global fashion brand.
The company has been particularly focused on the North American, Asian and Australian markets. In the last year, it opened two outlets in New York, with one located on Madison Avenue, and two stores in Toronto. Reiss also entered the Australian and French markets for the first time.
David Reiss, founder and chairman of Reiss, said: "Reiss performed strongly in the Christmas period, benefiting from our excellent product offering and international expansion driving business. We are pleased more and more customers are appreciating our offer.
"As we enter 2017, we look forward to working with our new partners at Warburg Pincus to expand the business further into a truly global fashion brand."