Objective: To examine the independent and joint relationships of poor subjective sleep quality and antepartum depression with suicidal ideation among pregnant women. Methods: A cross-sectional study was conducted among 641 pregnant women attending prenatal care clinics in Lima, Peru. Antepartum depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 scale. Antepartum subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Logistic regression procedures were performed to estimate odds ratios (aOR) and 95% confidence intervals (95% CI) adjusted for confounders. Results: Overall, the prevalence of suicidal ideation in this cohort was 16.8% and poor subjective sleep quality was more common among women endorsing suicidal ideation as compared to their counterparts who did not (47.2% vs. 24.8%, P< .001). After adjustment for confounders including maternal depression, poor subjective sleep quality (defined using the recommended criteria of PSQI global score of > 5 vs. ≤ 5) was associated with a 1.7-fold increased odds of suicidal ideation (aOR=1.67; 95% CI 1.02-2.71). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in an 18% increase in odds for suicidal ideation, even after adjusting for depression (aOR=1.18; 95% CI 1.08-1.28). Women with both poor subjective sleep quality and depression had a 3.5-fold increased odds of suicidal ideation (aOR=3.48; 95% CI 1.96-6.18) as compared with those who had neither risk factor. Conclusion: Poor subjective sleep quality was associated with increased odds of suicidal ideation. Replication of these findings may promote investments in studies designed to examine the efficacy of sleep-focused interventions to treat pregnant women with sleep disorders and suicidal ideation.