Langley was elected by a healthy majority of votes twice to the United States House of Representatives as a representative from Kentucky during the Seventieth and Seventy-first sessions of Congress, serving from March 4, 1927 through March 3, 1931. Because of her husband's conviction and disgraceful resignation, she was marginalized in social circles that once had accommodated her flamboyant style: a reporter wrote of "her unstinted display of gypsy colors on the floor." Her physical presence became the target of derision by the Washington elite, and her Kentucky-style oratory was also attacked. During her tenure as a Representative, she missed a third (52 out of 174) of the roll-call votes. Her committee appointments were Claims, Invalid Pensions, and Immigration and Naturalization as well as the Committee on Education. While in Congress she supported women's issues and advocated for the creation of a cabinet-level department of education. In 1930 Katherine Langley was the first woman to serve on the Republican Committee on Committees in the U.S. House of Representatives.