| Fetchwikidata: | ALL |
| Birth Place: | Gmina Grodzisk Mazowiecki, Polish–Lithuanian Commonwealth |
| Death Place: | Kraków, Polish–Lithuanian Commonwealth |
Grzegorz Knapski (Knapiusz, Cnapius; 1561–1639) was a Polish Jesuit, teacher, philologist, lexicographer and writer.
His most important work is the Thesaurus Polono-Latino-Graecus. First published in 1621 in Kraków, second edition in 1643 also in Kraków, it became a standard reference work in Polish schools and universities until the 18th century.