<p>Carnosic acid, a natural polyphenolic diterpene isolated from rosemary (<i>Salvia rosmarinus</i> Spenn., syn. <i>Rosmarinus officinalis</i> L., Lamiaceae), has been proven to possess a broad spectrum of pharmacological activities described in the scientific literature, being a major target for the development of new therapeutic products. Carnosic acid has been reported to possess multifaceted pharmacological activities, namely, antioxidant, antihyperglycemic, anti-inflammatory, antimicrobial, anti-obesity, antitumor/cytotoxicity, and neuroprotective activities. Carnosic acid also exhibits immense potential as a therapeutic agent in the prevention and treatment of many diseases such as numerous cancers, infectious diseases, and newly emerging illnesses like Alzheimer’s and Parkinson’s diseases. This manuscript aims to provide an updated literature review of the current state of research on carnosic acid, elucidating its most relevant biological activities, along with their molecular mechanism and various novel delivery carriers explored to improve its bioavailability and efficacy. Despite these encouraging findings, however, low water solubility and poor bioavailability of carnosic acid limit its <i>in vivo</i> activity; hence, an overview of different carriers employed to improve its efficacy is also furnished.</p> Graphical Abstract <p></p>