Walter Breuning (born September 21, 1896) is an American supercentenarian, and, at the age of 112 years, 301 days, one of the 15 oldest verified living people in the world and the oldest living man in the world (following the death of the British World War I veteran Henry Allingham). He is the oldest man in the United States following the December 27, 2008 death of George Francis. As of March 2009, he is also one of the 20 oldest men ever. On his 110th birthday, Breuning was declared the oldest living retired railroader in the United States. The governor of Montana, Brian Schweitzer, and the city mayor attended his celebration. He is the last known surviving man of 1896.
He worked fifty years for the Great Northern Railroad and its successor companies. During his early years, Breuning commented that he would have to hide from owner James J. Hill, as Hill didn't want any railroad employees under age 18 (Breuning began working in 1913, at that time being 17).
Having lived at the Rainbow Retirement and Assisted Living Center in Great Falls, Montana for the last 30 years, Breuning is in excellent health. He is able to walk, eats two meals a day, and always wears a suit and tie. He still maintains a sharp mind and accurate memory. In November 2007, at the age of 111, Breuning was fitted with hearing aids. On his 112th birthday, Breuning said the secret to long life is being active: "(if) you keep your mind busy and keep your body busy, you're going to be around a long time."
On February 16, 2009, Breuning made an appearance on the News Hour with Jim Lehrer giving his views about the current state of the economy and the newly elected president.
On April 24, 2009, Breuning was the focus of a segment done by Steve Hartman's "Assignment America" on the CBS Evening News.
On July 18, 2009, Breuning became the oldest man following the death of Henry Allingham.