In 1954, Griffiths was elected as a Democrat from Michigan's 17th congressional district to the 84th Congress and was subsequently re-elected to the nine following Congresses, serving from January 3, 1955 to December 31, 1974 in the U.S. House. She sat as a delegate at the Democratic National Convention in 1956 as well as in 1968. She was not a candidate for re-election to the 94th Congress in 1974.