Tom Sietas (born 12 January 1977 in Hamburg, Germany) is a freediver.
He specializes in the static apnea event, holding his breath under water, and the dynamic apnea event, swimming the greatest possible distance underwater without breathing.
Sietas started free diving in the year 2000.
Since then he has set many world records and won many titles, including taking the world record from magician David Blaine about four and a half months after his much-publicised achievement in mid-2008.
Sietas went on to add over five minutes to that record, which stood at 22:22 minutes when it was broken by Goran Colak.