Objectives: The primary objective of the proposed systematic review is to determine if there is an association between internalizing disorders and symptoms (ie, subclinical symptoms) and migraine in children and adolescents., Methods: We will perform a peer-reviewed Peer Review of Electronic Search Strategies search of MEDLINE, Embase, PsycINFO, and CINAHL from inception to December 2019. The authors will also review all reference lists of included studies for relevant citations. Observational studies on the association of pediatric migraine with internalizing disorders and symptoms will be included in this review. Case-control, cohort, and cross-sectional studies that include participants aged 18 years and under will be eligible for inclusion. The primary outcome for this systematic review will be migraine and the exposures of interest will include internalizing disorders (eg, major depressive disorder, dysthymia, generalized anxiety disorder, and post-traumatic stress disorder) and internalizing symptoms (depression symptoms, anxiety symptoms, obsessive compulsive symptoms, and post-traumatic stress symptoms). Two investigators will independently carry out an initial screen of abstracts, followed by a second screen of full-text manuscripts. Data extraction will be completed by 2 independent investigators. Study quality will be assessed using the Newcastle-Ottawa criteria for case-control and cohort studies and using a modified version of the Newcastle-Ottawa criteria for cross-sectional studies. A narrative synthesis of the data will be provided and, if possible, data will be quantitatively summarized using appropriate meta-analytic methods. Throughout the manuscript, the Preferred Reporting Items for Systematic Review and Meta-Analysis reporting standards will be followed., Results: The goal of this systematic review will be to provide a narrative, and if possible, quantitative summary on the association between pediatric migraine and internalizing disorders and symptoms., Conclusions: The methods applied in this systematic review protocol can be used to inform the design of future systematic reviews of observational studies in headache medicine. The results of this systematic review will be used to inform the clinical community on the association between pediatric migraine and internalizing disorders and symptoms and may also be used to inform the design of future research studies in this area., (© 2020 American Headache Society.)