Background: This study examined the incidence and clinical correlates of suicidal ideation (SI) in youth with tic disorders (TD). The independent contribution of tics, anxiety, depressive and externalizing symptoms on SI severity in youth with TD was assessed. Method: Participants were 75 treatment-seeking youth with a TD (N=75) aged 6-18. Participants completed diagnostic assessments, clinician-ratings, self- and parent-report measures of emotional functioning and the presence and/or severity of suicidal ideation. Results: Based on youth-report, 61% of youth endorsed at least some symptoms of SI, and 8% endorsed symptoms that exceeded the clinically significant cut-off. Parents reported SI in 11% of cases, with generally poor agreement between parent- and youth-report. Suicidal ideation correlated with higher anxiety, depressive and externalizing symptoms, affective lability, and with poorer distress tolerance and overall functioning. Anxiety, depressive and externalizing symptoms showed an independent relationship with SI. Tic severity was not associated with SI. Rather, higher tic severity was associated with an increase in anxiety symptoms, which in turn, was associated with greater SI severity. Limitations: Cross-sectional data limits causal conclusions. Diagnosis was based on unstructured assessments by expert clinicians, including consensus diagnosis, rather than structured clinical interviews. Conclusions: Around 8-11% of youth with TD experienced SI. Tic severity did not have any direct influence on SI, however the presence of comorbid anxiety and depressive symptoms significantly increases this risk. Results suggest that it is psychiatric comorbidity, rather than tics themselves, that predispose youth with tic disorders to increased risk of suicidality.