Catryna Louise Bilyk (born 7 February 1959) is an Australian politician. She has been a Labor member of the Australian Senate since July 2008, representing the state of Tasmania.
Bilyk was elected to serve a six-year term in the Senate at the 2007 federal election, after being placed in the third position on the Australian Labor Party's Tasmanian ticket. She was elected to the sixth Senate seat for Tasmania, on preferences distributed from Andrew Wilkie, the Australian Greens' second candidate for the Senate in Tasmania in the 2007 election. It was second time lucky for Bilyk, who had also been preselected in third spot on the Labor Senate ticket in Tasmania at the 2001 federal election, but failed to win a seat.
Bilyk was born in Hobart. She worked as an industrial officer for trade unions and has been ALP National Vice-President. She has worked as a nurse and a child carer. She is married with two adult children. In March 2008, she was diagnosed with two benign brain tumours, which were surgically removed.