The feat was broadcast live during The Oprah Winfrey Show and the studio audience cheered as divers pulled the 35-year-old magician from a water-filled sphere.
Blaine looked relaxed afterward and said the record was "a lifelong dream."
The previous record was 16 minutes and 32 seconds, set Feb. 10 by Switzerland's Peter Colat, according to Guinness World Records.
Before he entered the sphere, Blaine inhaled pure oxygen through a mask to saturate his blood with oxygen and flush out carbon dioxide.
Guinness says up to 30 minutes of so-called "oxygen hyperventilation" is allowed under its guidelines.
Previously, Blaine was buried alive for a week in a see-through coffin in New York and spent more than a month suspended from a glass box by the River Thames in London.