Frank Edward Guernsey (October 15, 1866 – January 1, 1927) was a U.S. Representative from Maine.
Born in Dover, Maine, Guernsey attended the common schools, Foxcroft Academy, Eastern Maine Conference Seminary, Bucksport, Maine, Wesleyan Seminary, Kents Hill, Maine, and Eastman's College, Poughkeepsie, New York. He studied law. He was admitted to the bar in 1890 and commenced practice in Dover, Maine. Treasurer of Piscataquis County 1890-1896. He served as member of the State house of representatives 1897-1899. He served in the State senate in 1903. He served as delegate to the Republican National Convention in 1908.
Guernsey was elected as a Republican to the Sixtieth Congress to fill the vacancy caused by the death of Llewellyn Powers. He was reelected to the Sixty-first and to the three succeeding Congresses and served from November 3, 1908, to March 3, 1917. He did not run for reelection but was an unsuccessful candidate for the Republican nomination for Senator. He served as president of the Piscataquis Savings Bank and trustee of the University of Maine. He also engaged in the practice of law. He died in Boston, Massachusetts, January 1, 1927. He was interred in Dover Cemetery, Dover-Foxcroft, Maine.