The Washington Mystics are an American professional basketball team based in Washington, D.C. The Mystics compete in the Women's National Basketball Association (WNBA) as a member club of the league's Eastern Conference. The team was founded prior to the 1998 season, and is owned by Monumental Sports & Entertainment (led by Ted Leonsis), which also owns the Mystics' NBA counterpart, the Washington Wizards. The team plays in the Entertainment & Sports Arena in the Congress Heights neighborhood of Washington DC. Sheila C. Johnson, co-founder of BET and ex-wife of Charlotte Sting owner Robert L. Johnson, is the managing partner.

The Mystics have qualified for the WNBA Playoffs in 13 of its 23 seasons of existence, and the franchise has been home to such high-quality players as two-time WNBA MVP Elena Delle Donne, Tennessee standout Chamique Holdsclaw, athletic shooting guard Alana Beard, and nearby Maryland product Crystal Langhorne. Until 2018, the Mystics were the only current WNBA franchise that had never made it to the WNBA Finals. They lost in the semifinals twice, to New York in 2002 and to the eventual champion Minnesota Lynx in 2017. After reaching the WNBA Finals for the first time in 2018, they won their first championship in 2019.