James Hamilton Leithauser (born April 15, 1978) is an American singer, songwriter, and multi-instrumentalist. He is the lead vocalist of the American indie rock band The Walkmen, with whom he wrote and recorded seven studio albums from 2000 to 2014. Prior to The Walkmen's formation, Leithauser and bass guitarist and organist, Peter Matthew Bauer, were both members of The Recoys. Leithauser was born and raised in Washington, DC, and has lived in New York City since the 1990s.

Leithauser embarked upon a solo career in 2014, releasing his debut studio album, Black Hours, on June 3, written and recorded alongside his Walkmen bandmate Paul Maroon. In 2016, Leithauser collaborated with former Vampire Weekend multi-instrumentalist Rostam Batmanglij on the studio album, I Had a Dream That You Were Mine. It was released to widespread critical acclaim later that year. He released the studio album The Loves of Your Life in 2020.