Findings on racial and ethnic differences in perinatal depression/anxiety are mixed. We assessed racial and ethnic differences in depression, anxiety, and comorbid depression/anxiety diagnoses in the year before, during, and the year after pregnancy (n = 116,449) and depression severity during (n = 72,475) and in the year after (n = 71,243) pregnancy among patients in a large, integrated healthcare delivery system. Compared to Non-Hispanic White individuals, Asian individuals had lower risk of perinatal depression and anxiety (e.g., depression during pregnancy relative risk [RR] = 0.35, 95 % confidence interval [CI]:0.33-0.38) and postpartum moderate/severe (RR = 0.63, 95 % CI:0.60-0.67) and severe (RR = 0.66, 95 CI:0.61-0.71) depression but higher risk of moderate/severe depression during pregnancy (RR = 1.18, 95 % CI:1.11-1.25). Non-Hispanic Black individuals had higher risk of perinatal depression, comorbid depression/anxiety, and moderate/severe and severe depression (e.g., depression diagnoses during pregnancy RR = 1.35, 95 % CI:1.26-1.44). Hispanic individuals had lower risk of depression during pregnancy and perinatal anxiety (e.g., depression during pregnancy RR = 0.86, 95 % CI:0.82-0.90) but higher risk of postpartum depression (RR = 1.14, 95 % CI:1.09-1.20) and moderate/severe and severe depression during and after pregnancy (e.g., severe depression during pregnancy RR = 1.59, 95 % CI:1.45-1.75). Information on depression severity was unavailable for some pregnancies. Findings may not generalize to individuals without insurance or outside of Northern California. Non-Hispanic Black individuals of reproductive age should be targeted with prevention and intervention efforts aimed at reducing and treating depression and anxiety. Asian and Hispanic individuals of reproductive age should be targeted with campaigns to destigmatize mental health disorders and demystify treatments and systematically screened for depression/anxiety.