The 2016 Washington Republican presidential primary was held on May 24 in the U.S. state of Washington as one of the Republican Party's primaries ahead of the 2016 presidential election. The only candidate on the ballot who had not withdrawn was Donald Trump.

Presidential primaries and caucuses of the Republican Party took place within all 50 U.S. states, the District of Columbia, and five U.S. territories between February 1 and June 7, 2016. These elections selected the 2,472 delegates that were sent to the Republican National Convention. Businessman and reality television personality Donald Trump won the Republican nomination for president of the United States.