Dana Whitney Vollmer (born November 13, 1987) is a former American competition swimmer, five-time Olympic gold medalist, and former world record-holder.

At the 2004 Summer Olympics, she won a gold medal as a member of the winning United States team in the 4×200-meter freestyle relay that set the world record in the event.

Vollmer won a total of thirty two medals in major international competitions, including nineteen gold medals, eight silver, and five bronze, spanning the Olympics, the World Championships, the Pan American Games, the Pan Pacific Championships, and the Goodwill Games, making her one of the most decorated female Olympians in swimming.

As an age group swimmer, Vollmer swam for coach Ron Forrest at the Fort Worth Area Swim Team (FAST).

In 2003, Vollmer underwent heart surgery to correct a condition called supraventricular tachycardia, which produces a quickened pulse rate of about 240 beats per minute.

At the 2004 Summer Olympics in Athens, Greece, Vollmer won a gold medal as a member of the winning U.S. team in 4×200-meter freestyle relay, together with Natalie Coughlin, Carly Piper and Kaitlin Sandeno.

In addition to winning the gold medal, the U.S. relay team broke the previous world record in the event that had stood for 17 years.

In her first event, the 4×100-meter freestyle relay, Vollmer won a silver medal with Natalie Coughlin, Jessica Hardy, and Missy Franklin.

In the 4×100-meter medley relay, Vollmer the gold medal along with Natalie Coughlin, Rebecca Soni, and Missy Franklin with a time of 3:52.36, better than three seconds ahead of second-place finisher China.

In her final event, the 4×100-meter medley relay, Vollmer won another gold with Missy Franklin, Rebecca Soni and Allison Schmitt.

The U.S. team of her, Simone Manuel, Abbey Weitzeil, and Katie Ledecky won silver with an American record time of 3:31.89.

[17] The couple announced they were expecting their first child on October 10, 2014, and she gave birth on March 6, 2015 to baby boy Arlen Jackson Grant.