•XLMTM is a severe subtype of congenital muscle disease caused by mutations in the myotubularin (MTM1) gene.•XLMTM is associated with characteristic pathology (increased central nuclei, hypotrophy, and organelle disorganization).•Several exciting therapeutic strategies have been identified for XLMTM.•Natural history studies have helped define clinical characteristics and outcome measures.•The first clinical trials for XLMTM are current underway, and hold therapeutic great promise. X-linked myotubular myopathy (XLMTM) is a severe congenital muscle disease caused by mutation in the MTM1 gene. MTM1 encodes myotubularin (MTM1), an endosomal phosphatase that acts to dephosphorylate key second messenger lipids PI3P and PI3,5P2. XLMTM is clinically characterized by profound muscle weakness and associated with multiple disabilities (including ventilator and wheelchair dependence) and early death in most affected individuals. The disease is classically defined by characteristic changes observed on muscle biopsy, including centrally located nuclei, myofiber hypotrophy, and organelle disorganization. In this review, we highlight the clinical and pathologic features of the disease, present concepts related to disease pathomechanisms, and present recent advances in therapy development.