Peter William Vanderkaay (born February 12, 1984) is an American former competition swimmer who specialized in middle-distance freestyle events and is a four-time Olympic medalist.

At the 2005 World Aquatics Championships in Montreal, Quebec, Vanderkaay won a gold medal in the 4×200-meter freestyle relay.

[6] At the 2007 World Aquatics Championships in Melbourne, Australia, Vanderkaay again swam in the relay with Lochte, Phelps, Keller.

[7] In the summer of 2007, Vanderkaay posted a career performance at U.S. Nationals, beating Michael Phelps for first place in the 400-meter freestyle.

Vanderkaay was part of the 4×200-meter freestyle relay that set the world record as the American team finished first with a time of 6:58.56.

The Americans were the first team to break the seven-minute mark in the relay, and broke the previous record, set in Melbourne by more than four and a half seconds.

At the 2012 Summer Olympics in London, Vanderkaay won a bronze medal in the 400-meter freestyle with a time of 3:44.69, finishing third behind Sun Yang and Park Tae-Hwan.