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.

Following Trump's victory in Washington and a surge in his support from unbound North Dakota delegates, the Associated Press (on May 26) announced that Trump had passed the threshold of 1,237 delegates required to guarantee his nomination.

[1] The Washington Republican State Convention was held May 19–21, 2016 in Pasco, WA.

Delegates to the Republican National Convention[2] were elected from among the approximately 3,000 delegates and alternates who had been elected to the Washington Republican State Convention.

[3] Winner: Donald Trump Primary date: May 24, 2016 Margin of error: ± 4% Sample size: 523 Margin of error: ± 5.1% Sample size: 372