What country has won the most Contract Bridge world championships?

The USA has won more contract bridge world championships than any other country.

However, the question is complicated. There are many bridge competitions listed as "world events." At each, there may be many categories of competition: both pairs and team competitions comprised of open, women's, mixed, senior and youth trophies. The World Bridge Federation (WBF) hosts the World Bridge Series Championships (WBSC), the most prestigious world championship events. Contested every four years since 1962, the WBSC now determines 13 world champions by nationality in the above-listed categories.

The Bermuda Cup, awarded to the winning open team, is the oldest, most frequently contested, and most widely acknowledged, WBF world championship. The Bermuda Cup has been contested 40 times since its inaugural year of 1950 (the Bermuda Cup became part of the WBSC in 1962). The USA has won the Bermuda Cup 18 times, followed by Italy (14), the Netherlands and France (2 each) and Great Britain, Norway, Brazil and Iceland (1 each).