The 1983 United States Senate special election in Washington was a special election held to fill the seat which had been held by longtime Senator Henry Jackson, who unexpectedly died on Three-term former Governor Dan Evans was appointed by Governor John Spellman on and he won the special election over congressman Mike Lowry on Jackson had won a sixth term the previous year, so more than five years remained in the term.
The legislature ordered a primary election on it featured 33 candidates (19 Democrats, 13 Republicans, and one Socialist Labor), setting the modern record for number of candidates in a Washington U.S. Senate election.
As of , this was the last time King County voted for a Republican U.S. Senate candidate. This was the first time since 1923 that Republicans held both Senate seats in the state.