Zakaznik (Russian: зака́зник, зака́зники, transliterated: zakaznik, zakazniki; Ukrainian: singular: заказни́к or зака́зник; plural: заказники́ or зака́зники, transliterated: zakaznyk, zakaznyky; Belarusian: заказнік, заказнікі, transliterated: zakaznik, zakazniki) is a type of protected area in former Soviet republics such as Belarus, Russia, and Ukraine^[1] that meets World Conservation Union's (IUCN) category IV, or more frequently category VI criteria.^{[citation needed]}

Many zakazniks have traditionally been managed as game reserves. Some protect complex ecosystems, colonies of birds, or populations of rare plants. They range in size from 0.5 ha to 6,000,000 ha. In other words, a zakaznik is a nature reserve.

Zakazniks are the areas where temporary or permanent limitations are placed upon certain on-site economic activities, such as logging, mining, grazing, hunting, etc. They correspond to sanctuary in UNESCO World Heritage terminology and literally mean preserves or reserve (from the Russian zakaz — order, reserve).