Jakub Kosakowski is a Polish chess grandmaster, born on January 7, 2002, and one of the most prolific medal winners in Polish youth chess. He took five medals at the Polish Youth Championships - including golds in the under-10, under-14 and under-16 groups - and eight more at the national youth rapid championships, six of them gold.

He added five medals in the national youth blitz championships and converted that junior pedigree into the Grandmaster title in 2025.