Yes. The governor signed a bill into law March 25, 2020, making Washington the 21st state to legalize sports betting. The bill legalizes sports betting in tribal casinos, though mobile wagering is only allowed inside those casinos.
There are 29 Native American casinos in Washington that can begin taking wagers, but a launch date has yet to be specified. Before that happens, tribes have to negotiate amendments to their gaming compacts with the state so sports betting can be added to their authorized activities. The hope for residents is that sports betting is launched ahead of the 2020 football season, but due to the Coronavirus pandemic, projecting a start date is a little more difficult.
Included in the bill are restrictions that prohibit betting on games involving in-state collegiate teams and minor league sports.
Oddly, Daily Fantasy Sports have yet to be legalized in Washington, though that's likely to change following the passing of the sports betting bill. As it stands, DFS sites are barred from entering the state because state laws determine that fantasy sports are a game of chance, in turn making them gambling. Since fantasy sports have yet to be permitted by the state as a method of gambling, they are considered illegal.
Otherwise, Washington allows horse betting and has racetracks as well as online options.