Purpose The aim of this study was to explore the relationship between parental mental illness in childhood with suicidal and self-harm ideations in adults seeking help for their tinnitus and/or hyperacusis. Method This was a retrospective, cross-sectional study. The data for 292 consecutive patients who attended a Tinnitus and Hyperacusis Therapy Specialist Clinic in the United Kingdom were included. Results Forty-six of 292 patients, or 15.75% of the patients, expressed that they have been bothered by suicidal and self-harm ideations within the last 2 weeks. Furthermore, 38.7% of the patients (113/292) reported that, while they were growing up during the first 18 years of life, their parent(s) were suffering from a mental illness. Logistic regression analysis showed a significant relationship between suicidal and self-harm ideations and the history of parental mental illness after adjusting the model for (a) tinnitus disability as measured via the Tinnitus Handicap Inventory (Newman, Jacobson, & Spitzer, 1996), (b) hyperacusis as measured via the Hyperacusis Questionnaire (Khalfa et al., 2002), (c) anxiety as measured via the Generalized Anxiety Disorder Questionnaire (Spitzer, Kroenke, Williams, & Löwe, 2006), (d) depression as measured via the Patient Health Questionnaire (Kroenke, Spitzer, & Williams, 2001), and (e) age and gender. Adjusted odds ratio was 2.5 (95% CI [1.14, 5.6], p = .022). The only other variable that was significantly related to the risk of suicidal and self-harm ideations was depression; adjusted odds ratio was 7.7 (95% CI [2.6, 26.3], p = .001). Conclusions Clinicians who offer tinnitus and hyperacusis rehabilitation should screen for suicidal and self-harm ideations among patients, especially for those with symptoms of depression and a childhood history of parental mental illness. Patients with suicidal and self-harm ideations should be referred to mental health services for further diagnosis and treatment.