Kazik may refer to:
- Slavic first name, a diminutive of Kazimierz (Polish) or Kazimir (Russian)
- Kazik Staszewski
- Kazik Radwanski
- Nom de guerre of Simcha Rotem, a member of the Jewish underground in Warsaw during World War II
- Kazimierz J. Kasperek, veteran from the Polish Navy who was fighting during World War II
- Wanda Gertz, Polish female soldier who served in the Polish Legion during World War I while masquerading as a man, under the name "Kazimierz 'Kazik' Zuchowicz"
- Alternative Romanization for Gazik, a Persian-language place name
- Kazik, Kecik, a dialect of Chulym language and a tribe which gave the name to the dialect