Objective: To describe access to Ontario midwifery care based on socio-economic status.Design: Two retrospective cohort studies.Setting: Ontario, Canada.Participants: (1) All Ontario midwifery billable courses of care discharged between April 1, 2006, and March 31, 2017 (N = 187,009), and (2) all Ontario residents who gave birth (≥ 20 weeks) in Ontario between April 1, 2012, and March 31, 2017 (N = 699,843). Data Sources: The Ontario Midwifery Program Legacy Database and the Better Outcomes Registry & Network’s Ontario perinatal registry.Measurements and Findings: We used residential postal codes to assign socio-economic status quintiles, using the Ontario Marginalization Index’s material deprivation measure. Between 2006 and 2017, the proportion of midwifery clients in the two least-marginalized quintiles was consistently greater than the proportion of midwifery clients in the two most-marginalized quintiles. Between 2012 and 2017, physicians cared for a larger proportion of people in the most-marginalized quintile than midwives, while midwives cared for a larger proportion of people in the least-marginalized quintile. Key Conclusions: People of low socio-economic status in Ontario are less likely to receive midwifery care than people of high socio-economic status. There was little change in this pattern over an 11-year period from 2006 to 2017.Implications: Efforts to reduce inequities in access to midwifery care should be prioritized and will require a multi-pronged approach that is supported by practicing midwives, government, midwifery stakeholder organizations, and other health care professionals. This article has been peer reviewed.