He competed for the Sydney Uni Water Polo Club in the Australia National Water Polo League winning three titles and for Club Natacio Barcelona in the Spanish League where he was equal highest goalscorer and won the Copa Del Rey in 2003.
Thomas competed for Club Atletic Barceloneta where he won the Copa Del Rey 2004, 2010 and League Title in 2010.
He played in the Italian League 2005–2009 with SS Nervi (2005-6) and Rari Nantes Savona (2006-2009).
Thomas Whalan served as a director of Water Polo Australia (WPA) 2012-2019 and on 25 November 2017.
This biographical article relating to an Australian water polo figure is a stub.