Heaney-Grier was born in Duluth, Minnesota to Bill and Renee Heaney. Her parents divorced when she was six years old. When she was eleven years old her mother remarried to Nelson Grier and in the summer of 1989, Heaney-Grier, along with her sister Erin, mother and new stepfather moved to the Florida Keys. When she was 16 years old, she legally changed her last name to Heaney-Grier.
Freediving
In 1996 at the age of 18 Heaney-Grier established the first constant weightfree-diving record in the United States with a dive to 155 feet on a single breath of air. The following year she beat her own record with a dive to 165 feet, When she set her second US record, the women's world record for free diving was 204.5 feet. In 1998 Heaney-Grier captained the first United States Freediving Team to compete in the World Cup Freediving Championships held in Sardinia, Italy. In 2000, Heaney-Grier was inducted as part of the inaugural roster into the Women Divers Hall of Fame.
Modeling
Heaney-Grier has modeled for, and been featured in, numerous catalogs and magazines including People, Outside, Life, Vogue Japan, Abercrombie & Fitch. She has also been a public relations ambassador for Omega Watches.
Television
In the late 1990s, Heaney-Grier partnered with her diving trainers, Manny Puig and Mark Rackley, filming underwater encounters with animals such as alligators and sharks. Rackley had worked as a spearfisherman and underwater videographer, and Puig had experience as an animal handler on movie sets and had learned how to ride and handle alligators in their environment. Together with Heaney-Grier, they formed a company named Extreme Encounters, and the footage they produced led to the Animal Planet series titled Extreme Contact. The 20 episode series featured the trio in cage-free encounters with sharks, alligators and other aquatic wildlife. They also worked on a USA Network one-hour special titled "Deep Diver: Tiger Shark Odyssey". In 2002, Heaney-Grier went on to other projects. In 1999 Heaney-Grier had a guest-starring role as a free-diver on an episode of Baywatch, and a starring role on a UPN movie of the week, Avalon:Beyond the Abyss, produced by Viacom Productions. Heaney-Grier has been a featured guest on the Late Show with David Letterman, London's TFI Friday, Primetime Live with Anderson Cooper and Ripley's Believe it or Not. Heaney-Grier also hosted Saturn's Gravity Files, covering the Gravity Games in 2004, and the Mad Fin Shark Series for ESPN in 2008. In 2015 Heaney-Grier co-starred as a member of a 5-person exploration team on the reality show , which documents the search for the legendary on Snake Island, Brazil.
