Background: Children with overweight/obesity are more likely to exhibit symptoms of depression and anxiety than are their peers without overweight/obesity; however, the rates and correlates of depression and anxiety symptoms among children seeking obesity treatment remain unclear. Objectives: Examine the prevalence and associated factors of depression and anxiety symptoms among treatment-seeking children with overweight/obesity. Methods: Children 7 to 11 years old (N = 241) and their parents completed assessments before beginning family-based behavioral weight-loss treatment. Disorder-specific self-report questionnaires assessed child depression and anxiety. The social-ecological model served as a framework for examining factors associated with depression and anxiety symptoms. Results: Among our sample, 39.8% (96/241) met clinical cutoffs for depression and/or anxiety symptomatology. Specifically, of these 96, 48 met criteria for both depression and anxiety, 24 for depression only, and 24 for anxiety only. Child eating disorder pathology, parents' use of psychological control (ie, a parenting style characterized by emotional manipulation), and lower child subjective social status were significantly associated with greater child depression symptomatology. Child eating disorder pathology and parent psychological control were significantly associated with greater child anxiety symptomatology. Conclusion: Nearly 40% of children exhibited psychopathology symptoms, and a variety of correlates were found. Thus, pediatric weight-loss providers may consider screening for and addressing mental health concerns (and associated factors) prior to and during treatment.