Ketamine's unique pharmacological profile, safety, modulation of multiple neurotransmitter systems, and ability to produce neuroplastic changes make it a subject of study with implications for a wide range of neuropsychiatric disorders beyond its traditional use as an anesthetic agent. This article aims to provide an overview of the pharmacology of ketamine and briefly discuss its emerging use in treating: substance use disorders (alcohol, cannabis, cocaine, and opioids); withdrawal syndromes (opioid and alcohol); acute and chronic pain syndromes; and severe psychomotor agitation. Ketamine for the treatment of depression and suicidality is well established; however, the focus of this paper is to outline less common indications.