The term biopolymer refers to materials obtained by chemically modifying natural biological substances or producing them through biotechnological processes. They are biodegradable, biocompatible and non‐toxic. Due to these advantages, biopolymers have wide applications in conventional cosmetics and new trends and have emerged as essential ingredients that function as rheological modifiers, emulsifiers, film‐formers, moisturizers, hydrators, antimicrobials and, more recently, materials with metabolic activity on skin. Developing approaches that exploit these features is a challenge for formulating skin, hair and oral care products and dermatological formulations. This article presents an overview of the use of the principal biopolymers used in cosmetic formulations and describes their sources, recently derived structures, novel applications and safety aspects of the use of these molecules.