Background: Alopecia areata (AA) is a chronic disease with an unpredictable course and can have a severe psychological impact on an individual. Objective: To provide evidence and consensus-based statements regarding the treatment of patients with AA in Korea. Methods: We searched for relevant studies from inception to May 2021 regarding the systemic treatment of AA. Evidence-based recommendations were also prepared. The evidence for each statement was graded and classified according to the strength of the recommendations. Hair experts from the Korean Hair Research Society (KHRS) voted on the statement, and an agreement of 75% or greater was considered as having reached consensus. Results: Current evidence supports the efficacy of systemic corticosteroids, oral cyclosporine monotherapy or combination with systemic corticosteroids, and oral Janus kinase inhibitors in severe AA patients. Systemic steroids may be considered for pediatric patients with severe AA. A consensus was achieved in three out of nine (33.3%), and one out of three (33.3%) statements pertaining to systemic treatment in adult and pediatric AA, respectively. Conclusion: The present study produced up-to-date, evidence-based treatment guidelines for AA associated with the consensus obtained by experts based on the Korean healthcare system.