OBJECTIVE Severe maternal morbidity (SMM) may be associated with postpartum psychiatric morbidity. However, the direction and strength of this relationship remain unclear. Our goal was to estimate the association between SMM and postpartum inpatient mental health care utilization. METHODS We examined all liveborn deliveries at a large, safety-net hospital in Atlanta, Georgia, from 2013 to 2021. SMM at or within 42 days of delivery was identified using International Classification of Disease codes. The primary outcome of interest was hospitalization with a psychiatric diagnosis in the year following the delivery. We used inverse probability of treatment weighting based on propensity scores to adjust for demographics, index delivery characteristics, and medical, psychiatric, and obstetric history. We fit log-binomial models with generalized estimating equations to calculate adjusted risk ratios (aRRs) and 95% confidence intervals (CIs). RESULTS Among 22,233 deliveries, the rates of SMM and postpartum hospitalization with a psychiatric diagnosis, respectively, were 6.8% (n = 1,149) and 0.8% (n = 169). The most common psychiatric diagnosis was nonpsychotic mood disorders (without SMM 0.4%, n = 79; with SMM 1.7% n = 24). After weighting, 2.2% of deliveries with SMM had a postpartum readmission with a psychiatric diagnosis, compared with 0.7% of deliveries without SMM (aRR: 3.2, 95% CI: [2.0, 5.2]). Associations were stronger among individuals without previous psychiatric hospitalization. CONCLUSIONS Experiencing SMM was associated with an elevated risk of postpartum psychiatric morbidity. These findings support screening and treatment for mild and moderate postpartum psychiatric disorders in the antenatal period. CONCLUSIONS · Experiencing SMM was associated with three-fold excess risk of postpartum psychiatric admission.. · Experiencing SMM was not associated with an elevated risk of outpatient psychiatric care use.. · Experience SMM was not associated with outpatient psychiatric morbidity diagnoses..