Background Childhood abuse is a major global and public health problem associated with a myriad of adverse outcomes across the life course. Suicide is one of the leading causes of mortality during the perinatal period. However, few studies have assessed the relationship between experiences of childhood abuse and suicidal ideation in pregnancy. Objective We sought to examine the association between exposure to childhood abuse and suicidal ideation among pregnant women. Study Design A cross-sectional study was conducted among 2964 pregnant women attending prenatal clinics in Lima, Peru. Childhood abuse was assessed using the Childhood Physical and Sexual Abuse Questionnaire. Depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 scale. Logistic regression procedures were performed to estimate adjusted odds ratios and 95% confidence intervals adjusted for potential confounders. Results Overall, the prevalence of childhood abuse in this cohort was 71.8% and antepartum suicidal ideation was 15.8%. The prevalence of antepartum suicidal ideation was higher among women who reported experiencing any childhood abuse compared to those reporting none (89.3% vs 10.7%, P < .0001). After adjusting for potential confounders, including antepartum depression and lifetime intimate partner violence, those with history of any childhood abuse had a 2.9-fold (2.90, adjusted odds ratio; 95% confidence interval, 2.12–3.97) increased odds of reporting suicidal ideation. Women who experienced both physical and sexual childhood abuse had much higher odds of suicidal ideation (adjusted odds ratio, 4.04; 95% confidence interval, 2.88–5.68). Women who experienced any childhood abuse and reported depression had 3.44-fold (3.44, adjusted odds ratio; 95% confidence interval, 1.84–6.43) increased odds of suicidal ideation compared with depressed women with no history of childhood abuse. Finally, the odds of suicidal ideation increased with increased number of childhood abuse events experienced (P value for linear trend < .001). Conclusion Maternal history of childhood abuse was associated with increased odds of antepartum suicidal ideation. It is important for clinicians to be aware of the potential increased risk of suicidal behaviors among pregnant women with a history of childhood physical and sexual abuse.