This work is a bibliographical review of rosemary (Rosmarinus officinalis) that focuses on the application of derivatives of this plant for cosmetic products, an application which has been recognized and valued since Ancient Egyptian times. Rosemary is a plant of Mediterranean origin that has been distributed throughout different areas of the world. It has many medicinal properties, and its extracts have been used (mainly orally) in folk medicine. It belongs to the Labiatae family, which contains several genera—such as Salvia, Lavandula, and Thymus—that are commonly used in cosmetics, due to their high prevalence of antioxidant molecules. Rosemary is a perennial shrub that grows in the wild or is cultivated. It has glandular hairs that emit fragrant volatile essential oils (mainly monoterpenes) in response to drought conditions in the Mediterranean climate. It also contains diterpenes such as carnosic acid and other polyphenolic molecules. Herein, the botanical and ecological characteristics of the plant are discussed, as well as the main bioactive compounds found in its volatile essential oil and in leaf extracts. Afterward, we review the applications of rosemary in cosmetics, considering its preservative power, the kinds of products in which it is used, and its toxicological safety, as well as its current uses or future applications in topical preparations, according to recent and ongoing studies.