Background: Temporomandibular disorders (TMD) are a group of musculoskeletal conditions that frequently affect the masticatory muscles and temporomandibular joints and often result in pain, dysfunction, and decreased quality of life. University students, particularly those in health-related fields, may be especially vulnerable to TMD owing to their elevated stress levels and the presence of oral parafunctional behaviors. Psychosocial factors such as anxiety and depression are recognized as important contributors to the onset and exacerbation of TMD symptoms. Methods: This cross-sectional study included 182 undergraduate students enrolled in medical and dental programmes at a private university in Brazil. The participants completed an online self-report questionnaire that included the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) Symptom Questionnaire, Oral Behavior Checklist (OBC), Generalized Anxiety Disorder Scale (GAD-7), and Patient Health Questionnaire (PHQ-9). Associations among TMD symptoms, oral behaviors, anxiety, and depression were analyzed using the chi-square and Fisher’s exact tests (α = 0.05). Results: A total of 78.6% of the participants reported TMD symptoms, with 38.5% experiencing both pain-related and joint-related symptoms. Oral behaviors were reported by 98.9% of the students, while symptoms of anxiety and depression were present in 74.7% and 65.4%of the sample, respectively. Significant associations were found between painful/joint TMD and higher levels of oral behaviors (p < 0.001), severe anxiety (p = 0.015), and moderately severe to severe depression (p = 0.016). Oral behaviors were more frequent in students in later semesters (p = 0.006) and were associated with anxiety (p < 0.001) and depression (p < 0.001). A strong correlation was observed between anxiety and depression (p < 0.001). Conclusions: This study confirmed a high prevalence of temporomandibular disorder (TMD) symptoms among medical and dental students. Pain-related and joint-related TMD symptoms were significantly associated with high-frequency oral behaviors, as well as with moderate to severe levels of anxiety and depression.