The 1978 United States Senate election in Kansas took place on November 7, 1978. Incumbent Republican Senator James B. Pearson did not run for re-election to a third full term.
Nancy Landon Kassebaum, the daughter of former Governor Alf Landon, won the election, defeating a large field of Republican candidates in the primary and Democratic former U.S. Representative William R. Roy in the general election.
Kassebaum became the first woman elected to a full term in the Senate without her husband having previously served in Congress. In fact, at the time of the election, she was separated from her husband John Philip Kassebaum. Their divorce was finalized in 1979, making Kassebaum the first single divorcée to serve in the U.S. Senate.