Stewart Gavin Haslinger (born 25 November 1981 in Ainsdale, Merseyside) is an English chess Grandmaster and former British Junior champion.

Now a resident of nearby Formby, Haslinger comes from a strong chess-playing family.

Taught by his father at four years of age, he became British under-12 champion in 1993, in step with the achievements of sisters Cathy and Mandy, who were British girls' junior champions across the range of age groups.

Haslinger finished a Master's degree in mathematics at Liverpool University in 2006 and decided to spend some time trying to become a chess Grandmaster.

He began his studies for a PhD in applied mathematics at the University of Liverpool in 2010 and was awarded it in 2014.