Suboptimal regimen adherence among youth with type 1 diabetes (T1D) is a common challenge for patients, families, and providers. Motivational interviewing (MI) is a brief communication style designed to elicit intrinsic motivation and strengthen commitment to behavior change goals. As pediatric MI research expands, a critical review of its evidence base and applicability to promote adherence behaviors for youth with T1D is needed. This review introduces the core tenets of MI and clinical applications in T1D, synthesizes the existing MI research in T1D, and discusses the next steps in MI research. Overall, mixed results for MI interventions in T1D reflect variations in research study design and clinical implementation. Targeting adherence rather than glycemic outcomes typically demonstrates greater results, highlighting the promise of MI to facilitate meaningful and enduring improvements in youths' T1D adherence behaviors.