The 1928 United States Senate election in Connecticut was held on November 6, 1928. Incumbent Republican Senator George P. McLean was not a candidate for re-election. In his place, Republican State Senator Frederic C. Walcott won the seat against former U.S. Representative Augustine Lonergan.
Lonergan would win an election to Connecticut's other Senate seat in 1932; he and Walcott served as colleagues in the Senate from 1933 to 1935.