According to Shams Charania of The Vertical, the 29-year-old joined the team on a one-year deal.
Washington will be the sixth NBA team Sloan has played for in six years in the league.
He spent the past year with the Guangdong Southern Tigers in China, but prior to that, he played the 2015-16 season with the Brooklyn Nets, appearing in 61 games while starting 33. He averaged 7.0 points and 4.4 assists per game, though he was significantly better after the All-Star break. His scoring went from 5.9 PPG in the first half of the year to 8.3 in the second.
The Wizards will hope he can provide some help off the bench next season, which was one of the weakest parts of last year's squad. Although John Wall and Bradley Beal were as fearsome backcourt as there is in basketball, the team struggled mightily when the second unit was on the court.
Brandon Jennings and Trey Burke are gone, but second-year players Tomas Satoransky and Sheldon McClellan could be asked to take on bigger roles in the rotation.
With the additions of Tim Frazier and now Sloan, there are several new options for the coaching staff to work with in 2017-18.
Although Sloan hasn't turned many heads in his career, the Texas A&M product could be a key part of the team's attempt to contend in the Eastern Conference.