Sebastian Marczak

{{short description|Australian canoeist}}

{{Use dmy dates|date=January 2019}}

{{Use Australian English|date=January 2013}}

Sebastian Marczak (born 4 January 1983 in Sydney) is an Australian sprint canoeist.{{refn|name=OlympicBotGeneratedRef|{{cite web|title=Sebastian Marczak|url=http://www.london2012.com/athlete/marczak-sebastian-1125496/|work=London 2012|publisher=The London Organising Committee of the Olympic Games and Paralympic Games Limited|accessdate=13 September 2012|url-status=dead|archiveurl=https://web.archive.org/web/20120913200657/http://www.london2012.com/athlete/marczak-sebastian-1125496/|archivedate=13 September 2012|df=dmy-all}}}} At the 2012 Summer Olympics, he competed in the Men's C-1 200 metres.