The 1942 United States Senate election in Arkansas took place on November 2, 1942. Incumbent Senator John E. Miller was appointed to a federal judgeship by Franklin Delano Roosevelt, and his appointed replacement Lloyd Spencer rejoined the Navy rather than run for election.
After a highly-competitive four-way primary, U.S. Representative John L. McClellan defeated Arkansas Attorney General Jack Holt in a run-off election.
Because the Republican Party (or any other party) did not field a candidate in the general election, McClellan's primary victory was tantamount to election.
McClellan was unopposed in the general election.