Pieter Cornelis Martijn van den Hoogenband (born March 14, 1978 in Maastricht) is a Dutch swimmer and a triple Olympic champion. He is the current world record holder in 100 m freestyle swimming (47.84 s).

Raised in Geldrop, near Eindhoven, Noord-Brabant, the son of Cees-Rein van den Hoogenband and Astrid Verver, a former Dutch 800 m freestyle silver medalist at the European Championships, Pieter grew up in Geldrop, where he swam for PSV Eindhoven. His father is a team doctor with the professional football team of the same club. In 1993, Van den Hoogenband achieved his first successes, performing well on the European Youth Olympic Days.

Prior to the Atlanta Games, Astrid van den Hoogenband, who was coaching the Dutch team, became frustrated with the swimmers representing the Netherlands, feeling they had much potential but would not be able to live up to it due to lack of adequate support. She pleaded with Cees to take action, as he carried much weight from his professional connections. After Astrid threatened to remove Pieter from the sport, Cees created a small foundation and signed up 20 initial sponsors who each paid $2,500 to fund a team trainer. The Dutch swimming team eventually signed extremely lucrative contracts with Philips, Nike, and Speedo. Enough funds were raised to open a swim school in Eindhoven, van den Hoogenband's place of residence. The team eventually grew to ten. Pieter remained the Netherlands' brightest star, and along with fellow Dutch Inge de Bruijn brought the Netherlands many victories in the sport.

His international breakthrough came at the 1996 Summer Olympics in Atlanta. Only 18 years old, van den Hoogenband surprised many by finishing 4th in both the 100 and 200 m freestyle.

After winning 6 gold medals at the 1999 European Championships, he was one of the favourites at the 2000 Summer Olympics, but his adversaries were formidable. In the 200 m freestyle, he faced Australian youngster Ian Thorpe, favourite of the home crowd in Sydney. In the semi-finals, van den Hoogenband set a new world record, but Thorpe countered with a time only 0.02s slower. In an exciting final, van den Hoogenband equalled his time from the semi-finals to win the gold medal. In the 100 m freestyle, van den Hoogenband again set a world record in the semi-finals and won his second gold medal, defeating the 1992 and 1996 champion, Alexander Popov. He won two more medals, both bronze, in the 50 m freestyle and the 4 x 200 m freestyle relay, in which he was the final swimmer.

He was named the 2000 Male World Swimmer of the Year by Swimming World magazine .

At the 2001 Aquatics World Championships, van den Hoogenband won four silver medals in the 50, 100, 200 and 4 x 100 m freestyle events. At the 2004 Summer Olympics in Athens, he won a gold medal in the 100 m freestyle and two silvers in the 200 m freestyle and the 4 x 100 m freestyle relay. His anchor leg of 46.79 in the 4x100m Freestyle Relay is the fastest split in history.

He and his wife, former medley swimmer Minouche Smit, had their first child, a daughter named Daphne, on June 23 2007.