This chapter focuses on medial epicondyle apophysitis, or Little League Elbow, a common overuse injury in young throwing athletes. It summarizes epidemiology, pertinent anatomy, biomechanics of throwing, etiology and risk factors, diagnostic tools (e.g., history, physical, imaging), and preventative strategies. Moreover, it provides up-to-date information on conservative management and associated rehabilitation, surgical options with associated rehabilitation, and outcomes including recurrence and return to sport.