Tamsin Barnett made her Olympic debut as an indoor volleyball player at the Sydney Olympic Games in 2000. Barnett was always a strong sportswoman, succeeding in rowing before taking up volleyball and playing in the European Professional Leagues. In 2003, the South Australian tore her meniscus, ruling her out of the Athens 2004 Olympic Games and hard court volleyball competitions. In 2004 she took up beach volleyball and won the 2005/2006 National Title with Sydney 2000 gold medallist Natalie Cook. Barnett and Cook placed fifth in Beijing in 2008 before being knocked out in the group stage of the London 2012 Games. Barnett had a grandfather selected to sail for the Netherlands in the Olympics but he was prevented from competing due to World War II.