Ralph Moody Hall (born May 3, 1923) is an American politician who served as the United States Representative for Texas's 4th congressional district from 1981 to 2015. He was first elected in 1980, and was the chairman of the House Committee on Science, Space and Technology from 2011 to 2013. He was also a member of the Committee on Energy and Commerce. In 2004, he switched to the Republican Party after having been a member of the Democratic Party for more than 50 years.
At 91, he was the oldest serving member of Congress at the end of his last term in office, the oldest person to ever serve in the House of Representatives, the oldest person ever elected to a House term and the oldest House member ever to cast a vote. He and Michigan Congressman John Dingell were the last two World War II veterans serving in Congress.