The tournament was first held on the men's tour in 1969, known as the Washington Star International from 1969 to 1981, the Sovran Bank Classic from 1982 to 1992, the Newsweek Tennis Classic in 1993, the Legg Mason Tennis Classic from 1994 to 2011, and the Citi Open from 2012 to 2022. Competition was held on outdoor clay courts until 1986 when it switched to the current hard courts. Co-founders
John A Harris and
Donald Dell, founder of ProServ International, have since remained closely involved. The location of the event in Washington, D.C., was chosen at the urging of
Arthur Ashe, an early supporter. The women's event was first held in 2011 in
College Park, Maryland, as the Citi Open, and for the 2012 season, the ATP and WTA decided to merge their Maryland and Washington spots into a joint tournament, with the women's event moving to the William H.G. FitzGerald Tennis Center, and
Citi replacing Legg Mason as title sponsor of the joint event. In 2015, the Washington Open dropped out of the
US Open Series because of disagreements with
ESPN, which that year took over broadcast rights to the
US Open and US Open Series events. ESPN would not commit to air more than four hours of the tournament on its
ESPN2 network; the remainer would be relegated to
ESPN3 online streaming. (In 2014, coverage was split between ESPN and
Tennis Channel.) Donald Dell criticized ESPN for using ESPN3 to acquire sports rights without any intent to broadcast them on television: "If you're running a tournament, and it's $2 million, and sponsorship money in the $6 million-to-$8 million range, you've got sponsors that don't want to be having only four or six hours on television." Citi Open organizers withdrew from the US Open Series so it could establish a new broadcast rights agreement with Tennis Channel. The four-year, $2.1 million deal included funding for additional amenities and 171 hours of television coverage. In 2019, the Washington Open was acquired by venture capitalist and USTA board member
Mark Ein. It returned to the US Open Series, and also signed a five-year extension of its media rights with Tennis Channel. The 2020 tournament was cancelled due to the
COVID-19 pandemic. The men's event returned for 2021, but the women's event remained cancelled; the WTA did not reinstate its sanctioning of the tournament due to conflicts with the
2020 Summer Olympics. The tournament instead organized a women's invitational, featuring
Coco Gauff,
Jessica Pegula, and
Jennifer Brady. In June 2023, Ein and
IMG announced that the Washington Open would merge with the
Silicon Valley Classic to form a single tournament in Washington, D.C.; this therefore promoted the Washington Open from a
WTA 250 event to a
WTA 500 event. Players had usually been divided between the two tournaments, as the Silicon Valley Classic was more prestigious, but the Washington Open was in closer proximity to the other tournaments of the North American hardcourt season. As a result of the merger, the Silicon Valley Classic's title sponsor
Mubadala Investment Company became a co-title sponsor of the event, and the tournament was renamed the Mubadala Citi DC Open. The tournament is the first-ever joint 500-level event on the ATP and WTA tours, and remains the only joint 500 event in the world. ==Past finals==