: To perform a systematic review of the application of botulinum toxin A (BTA) in the management of strabismus in the adult and pediatric populations. : A systematic literature search was performed using the Medline database. : In 1989, with the FDA approval of botulinum toxin (onabotulinum toxin A, or BTA) for the treatment of strabismus, patients were provided with an alternative to surgical recession. In this review, we discuss the uses of BTA in the treatment of acute onset comitant esotropia or smaller angle esotropia and as an adjunct to surgery for larger angle esotropia or sixth nerve palsy. Its uses are also explored in intermittent exotropia and vertical strabismus, including thyroid-associated orbitopathy, fourth nerve palsies, and other orbital pathology. : Despite its transient kinetics, BTA can have permanent effects on ocular alignment, promoting binocularity and reduction of diplopia, and can serve as a primary treatment or a muscle sparing option in patients at risk of anterior segment ischemia or need for future surgeries.