Mentha aquatica L., or water mint, is an important member of the Mentha genus, and has long been used in traditional medicine, mainly to treat respiratory diseases such as the common cold. Nevertheless, although over the years many studies have shown that it's potential grows beyond this use, a review that highlights M. aquatica L.'s true potential is still lacking. Thus, the main purpose of the present article is to provide a thorough and multidisciplinary critical review of M. aquatica L., including its phytochemical characterization, main bioactivities, and current marketed cosmetic products. Many compounds have been identified as part of M. aquatica L. composition, such as terpenes, phenolic acids, phenols, and terpenoids, which have been linked to a vast therapeutic potential, namely anti‐inflammatory, antioxidant, antibacterial, antifungal, antiobesity, and hepatoprotection bioactivities, with additional anticancer potential for several types of tumors (breast, lung, and skin), and psycho and neuroactive potential in depression, or Alzheimer's or Parkinson's disease. Additionally, it has been proven to be suitable for cosmetic application since several cleansing, hydrating, protecting, and/or odor masking products containing it are already available, with the main functions attributed to M. aquatica including refreshing/cooling effects, calming/soothing/relaxing effects, and purifying effects, properties closely related to its anti‐inflammatory and antioxidant bioactivities. Hence, M. aquatica is an extremely versatile plant, with its extracts and essential oils having great therapeutic and cosmetic potential. With many marketed cosmetic products, future studies should focus on this plant's medicinal aspects, so that 1 day it can be part of therapeutic regimens.