Background: Botulinum toxin (BoNT) is a potent biological exotoxin produced from Clostridium botulinum. Although it was first used therapeutically to treat strabismus, its clinical role has since expanded rapidly over the years to include treatment of a variety of head and neck, gastrointestinal, urogenital, musculoskeletal, neurological, dermatological, and cosmetic disorders. The main purpose of this review is to provide a brief updated overview of the history, mechanism of action, and clinical applications of BoNT therapy across multiple medical specialties, including the most common adverse effects and recommended Botox dosages. Methods: A literature review was conducted in the PubMed database limited to English language articles. Specific search terms related to botulinum toxin in combination with various subspecialty fields were used, and relevant articles were identified and analyzed. The reference section for each article was also searched to find additional articles. Results: BoNT is a powerful therapeutic tool and has a vast array of clinical uses in many specialties, including ophthalmology, neurology, plastic surgery, dermatology, orthopedic, gastrointestinal, gynecology, urology, and rheumatology. Due to its chemodenervation effects at the presynaptic nerve terminal, it is useful in treatments of disorders characterized by abnormal inappropriate muscle contractions. Conclusions: BoNT has many clinical applications in several medical specialties. Future studies should focus on any additional indications of BoNT therapy as they arise and on any novel product developments.