The Premier Hockey Federation (PHF) was a women's professional ice hockey league in the United States and Canada that operated from March 2015 until June 2023. The league was established in 2015 as the National Women's Hockey League (NWHL), comprising four league-owned teams. Over time, some teams gained independent ownership and the number of teams grew to seven; teams during the league's final season in 2022–23 included the Boston Pride, Buffalo Beauts, Connecticut Whale, Metropolitan Riveters, Minnesota Whitecaps, Montreal Force, and Toronto Six. The Isobel Cup was awarded annually to the league playoff champion.

Women's professional sports are a relatively new phenomenon, having largely emerged within the latter part of the 20th century. Unlike amateur female athletes, professional female athletes are able to acquire an income which allows them to earn a living without requiring another source of income. In international terms, most top female athletes are not paid and work full-time or part-time jobs in addition to their training, practice, and competition schedules. Professional organizations for women in sport are most common in developed countries where there are investors available to buy teams and businesses which can afford to sponsor them in exchange for publicity and the opportunity to promote a variety of their products. Very few governments support professional sports, male or female. Today there are a number of professional women's sport leagues in the United States and Canada.