Kosher Certification is the stamp of kosher approval by a rabbinic Agency verifying they have checked the products ingredients, production facility and actual production to ensure all ingredients, derivatives, tools and machinery have no trace of non kosher substances. The Kosher Certified symbol assures consumers that both the actual product and its production adhere to all Kosher Law requirements.

A kosher certification agency is an organization or certifying authority that grants a hechsher (Hebrew: הכשר‎, "seal of approval") to ingredients, packaged foods, beverages, and certain materials, as well as food-service providers and facilities in which kosher food is prepared or served. This certification verifies that the ingredients, production process including all machinery, and/or food-service process complies with the standards of kashrut (Jewish dietary law) as stipulated in the Shulchan Arukh, the benchmark of religious Jewish law. The certification agency employs mashgichim (rabbinic field representatives) to make periodic site visits and oversee the food-production or food-service process in order to verify ongoing compliance. Each agency has its own trademarked symbol that it allows manufacturers and food-service providers to display on their products or in-store certificates; use of this symbol can be revoked for non-compliance. Each agency typically has a "certifying rabbi" (Rav Hamachshir) who determines the exact kashrut standards to be applied and oversees their implementation.