Katharine Edgar Byron (October 25, 1903 – December 28, 1976), a Democrat, was a U.S. Congresswoman who represented the 6th congressional district of Maryland from May 27, 1941 to January 3, 1943. She was the first woman elected to Congress from Maryland.
Byron was born in Detroit, Michigan. She attended independent schools during her youth, such as the Westover School of Middlebury, Connecticut, and the Holton-Arms School of Bethesda, Maryland. She later moved to Williamsport, Maryland, in 1922. The Byrons were communicants of Saint John's Church. She was elected to Congress in a special election held May 27, 1941 to replace her husband, Representative William D. Byron, after his death in an airplane crash in Georgia on February 27, 1941. She was not a candidate for reelection and retired in Washington, D.C., which is where she also died. She is interred in Riverview Cemetery of Williamsport, Maryland.
Byron was a granddaughter of U.S. Senator Louis E. McComas; her son, Goodloe Byron, was also a representative from the 6th district.