| Joomla.pl | Masovian |
| JPConsulting.pl | |
| JSD Solutions Sp. z o.o. | |
| JSystems | |
| JT-Soft | Kuyavian-Pomeranian |
| Jujubee S.A. | Silesian |
| Junisoftex Sp. z o.o. | |
| Juo Sp. z o.o. | |
| jurXpert | Masovian |
| JustIdea | |
| Jutro Medical Sp. z o.o. | |
| JW Web Development | Kuyavian-Pomeranian |
| K2 Holding S.A. | Masovian |
| Kaban Tool | |
| Kaczka Studio | Silesian |
| KAFT | |
| Kalasoft | Greater Poland |
| Kambu Sp. z o.o. | |
| Kamee Sp. z o.o. | Lesser Poland |
| KamikStudio | |
| Kamilnotebook | Lower Silesian |
| Kamsoft S.A. | |
| Kangur Electronics | |
| Kantata Sp. z o.o. | Kuyavian-Pomeranian |
| Kantor.pl | |
| Karkonoska Akademia Nauk Stosowanych | |
| Karpato | |
| Kaszubsko-Pomorska Szkoła Wyższa w Wejherowie | |
| Katedra Informatyki i Automatyki | Subcarpathian |
| KateOS | Łódź |
| Katowicka Specjalna Strefa Ekonomiczna | |
| Katowicka Specjalna Strefa Ekonomiczna S.A. | |
| kbsw | |
| KCR S.A. | |
| KDS | Silesian |
| Kedar | Pomeranian |
| KelebekLabs Venture Studio | |
| Kempa Satellite Networks | Masovian |
| Key2Print | |
| KIAT.io | |
| Kielecki Park Technologiczny | |
| KielniaKodu | |
| KIM Group | Lesser Poland |
| Kingweb | Lesser Poland |
| KISS digital Sp. z o.o. | |
| Kivy Software Sp. z o.o. | |
| Kiwee Sp. z o.o. Sp.k. | Lower Silesian |
| Kiwwwi | |
| kkNET | Silesian |
| KLL | Silesian |