Background/Objectives: Temporomandibular disorders (TMDs) are a group of multifactorial conditions affecting the temporomandibular joints (TMJs), masticatory muscles, and associated structures. TMDs are identified as the main cause of non-dental orofacial pain in children and adolescents. This scoping review aims to explore recent evidence on prevalence, clinical presentation, associated factors, and treatment approaches of TMDs in children and adolescents. Methods: A systematic search was conducted across PubMed, Scopus and Embase for studies published between 2015 and 2025, following PRISMA-ScR guidelines. Results: Thirty-eight studies were included. TMD prevalence in children and adolescents ranged from 16.9% to 40% through clinical examination, with painful TMD rates ranging from 16.2% to 25.5%, while symptom-based surveys reported prevalences of 9–35.3%. The most frequent diagnoses were myofascial pain, myalgia, arthralgia and disc displacement with reduction. Female sex and increasing age were consistent risk factors. Psychosocial variables, such as anxiety and depression, showed strong associations with pain-related TMDs. Structural and systemic conditions such as musculoskeletal alterations, joint hypermobility, respiratory conditions and headaches/migraines were also frequently reported. Evidence on treatment appears to be limited. In juvenile idiopathic arthritis (JIA), TMJ involvement is prevalent (32.6–64%), particularly in the persistent oligoarticular subtype. Conclusions: TMDs in children and adolescents are prevalent and multifactorial conditions, mainly of muscular origin, presenting more frequently in adolescents and females. Psychosocial factors, functional habits, clenching, mouth breathing and systemic conditions may be associated with TMD presence or severity. Substantial heterogeneity persists in diagnostic criteria, assessment tools and outcome measures. Research on therapeutic interventions is scarce and often limited to small samples. Standardized diagnostic protocols, improvements in research consistency, longitudinal cohorts and RCTs are needed to clarify etiological pathways, validate diagnostic criteria and establish effective, evidence-based strategies for the management of TMDs in children and adolescents.