The Billie Jean King Cup is the women's national team tennis world championship, equivalent to the men's Davis Cup. Like the latter, it is organized by the International Tennis Federation.

Born in 1963 as the Federation Cup, it was known from 1995 to 2019 as the Fed Cup and in 2020 it was renamed in homage to the American tennis player Billie Jean King.

The idea for the event dates back to 1919, when Hazel Hotchkiss Wightman came up with the concept of a women's team event. This proposal was rejected and in 1923 she set up a trophy to be won every year between the United States and Great Britain, at the time the strongest nations in the world. Nell Hopman, wife of the legendary Australian Captain Harry Hopman, later took up Mrs Wightman's idea.

Initially there was no prize money and teams entered at their own expense. The advent of sponsors greatly increased the number of competing nations; the first was Colgate in 1976, then between 1981 and 1994 it was the turn of NEC. In 1994, 73 nations participated and it was required that the host nation that game week have a special tennis complex to organize it.

Since the 2020 edition, the format of the competition has changed. The main change involves the World Group, which takes place in a single venue and in a single week, with twelve teams divided into four groups of three teams each, with the winners of each group advancing to the semi-finals. The matches between the teams in this stage will feature two singles matches and one doubles match.

Since September 2020, the competition has also changed its name to the Billie Jean King Cup by BNP Paribas, in honor of the US champion and tennis icon. For the first time a world team competition will bear the name of a woman.