Klete Derik Keller (born March 21, 1982) is an American former competitive swimmer. Before retiring from swimming in 2008, Keller won five Olympic medals, including two golds, at the 2000, 2004, and 2008 Summer Olympics in the 400-meter freestyle and the 4×200-meter freestyle relay.
In January 2021, Keller took part in the 2021 United States Capitol attack. He was later arrested and charged with three offenses stemming from his participation. He was indicted on seven charges by a grand jury the following month, and later pleaded guilty to a single felony charge as part of a plea bargain. In December 2023, Keller was sentenced to three years of probation and six months of home detention.