Thomas Stalker Butler (November 4, 1855 – May 26, 1928) was an American politician who served as a U.S. Representative from Pennsylvania from March 4, 1897, until his death, having been elected to the House sixteen times. He was the father of the Marine Corps Major General Smedley Butler. He was Dean of the United States House of Representatives.

Butler was born in Uwchlan Township, Chester County, Pennsylvania. His father was Samuel Butler, a farmer and banker who served in the Pennsylvania House of Representatives and one term as Pennsylvania State Treasurer from 1880 to 1882. Thomas attended the common schools, West Chester State Normal School, and Wyer’s Academy in West Chester.

He later studied law, was admitted to the bar in 1877, and commenced practice in West Chester. From 1885 to 1889 and again in 1927-1928 he served as trustee of the West Chester State Normal School. Butler was appointed judge of the fifteenth judicial district of Pennsylvania in 1888.

Butler stood as an unsuccessful candidate for reelection in 1889. He was a delegate to the Republican National Convention in 1892.

Elected to Congress in his first term as an Independent Republican, he was elected as a Republican for each succeeding term. While in Congress, he was chairman of the United States House Committee on Pacific Railroads (Fifty-ninth through Sixty-first Congresses) and member of the United States House Committee on Naval Affairs (Sixty-sixth through Seventieth Congresses).

During World War I, Butler read into the Congressional Record the "bogus oath", which was falsely attributed to the Roman Catholic fraternal organization Knights of Columbus, in which the oath taker pledges to war against Protestant Christians.^[1] The bogus oath was refuted by the Committee on Public Information, the wartime information agency of the Woodrow Wilson administration.^[2]

Butler died in office and was buried in Oaklands Cemetery, West Chester, Pennsylvania. His home at West Chester, The Butler House, was listed on the National Register of Historic Places in 1980.^[3]

• List of United States Congress members who died in office (1900–49)