This study examined the psychiatric symptom, clinical, psychosocial, and sociodemographic correlates of suicidality in a trans-diagnostic sample of patients with psychotic spectrum disorders, including schizophrenia, schizoaffective disorder, psychotic disorder NOS, and bipolar disorder with psychotic features, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). Secondarily, the study assessed whether the symptom correlates of suicidality differed when examined a trans-diagnostic approach versus with the traditional diagnostic study design. The study sample comprised 181 patients at an inpatient psychiatric hospital who were assessed within four days of admission. Clinical assessments included the Brief Psychiatric Rating Scale-Expanded Version 4.0 (BPRS-E) and semi-structured assessments administered by inpatient staff. In the trans-diagnostic sample, BPRS-E scores on severity of BPRS-E Suicidality positively correlated with BPRS-E ratings of Depression, Anxiety, Guilt, Hallucinations, Suspiciousness, and BPRS-E total score (p ≤ .01). The mean adjusted severity of Suicidality scores in the schizophrenia group was significantly less than the psychotic disorder NOS group (p = .02). Within all four diagnostic groups, severity of Suicidality scores correlated with severity ratings of Depression (p < .05). Scores on BPRS-E Depression correlated with Suicidality ratings in the bipolar disorder group (p < .05). In the schizophrenia group, BPRS-E scores on Depression (p < .001) and Guilt (p < .05) correlated with Suicidality ratings. The schizoaffective disorder and psychotic disorder NOS groups replicated the trans-diagnostic sample in terms of symptom correlates of Suicidality scores, excluding BPRS-E Hallucinations in the former and Suspiciousness in the latter. Severity of BPRS-E Suicidality was positively associated with age, parental status, homelessness, and prior suicide attempts. The results suggest that suicidality is not pathognomonic, but transcends many diagnostic categories of the psychotic spectrum. Depression contributed to the suicidal drive across all psychotic spectrum disorders in our sample. Additionally, the schizoaffective disorder and psychotic disorder NOS groups had multidimensional and complex psychiatric symptom correlates of suicidality compared to the schizophrenia and bipolar disorder with psychotic features groups. These results may help clinicians implement risk reduction measures tailored to specific symptom correlates of suicidality both within diagnostic categories and in trans-diagnostic patient populations.