Guillermo Gorostiza Paredes (15 February 1909 – 23 August 1966) was a Spanish footballer who played as a forward.
In a 14-year professional career, he played for Athletic Bilbao and Valencia, amassing La Liga totals of 255 games and 178 goals and winning 11 major titles with the two teams combined.
Gorostiza appeared for Spain at the 1934 World Cup.