The 1948 United States Senate election in Maine was held on September 13, 1948. Incumbent Republican U.S. Senator and Senate Majority Leader Wallace White did not seek a fourth term in office. U.S. Representative Margaret Chase Smith defeated the two most recent Governors of Maine, Horace Hildreth and Sumner Sewall, in the Republican primary. In the general election, Smith resoundingly defeated Democrat Adrian Scolten of Portland.