In recent years, the United States has been experiencing historically high suicide rates. In the face of mental health care provider shortages that leave millions needing to travel longer to find providers with schedule openings, if any are available at all, the inaccessibility of mental health care has become increasingly central in explaining suicidality. To examine the relationship between access to care and suicide, we leverage a dataset mapping all licensed US psychiatrists and psychotherapists (N= 711,214), as of early 2020, and employ real-world transportation data to model patients’ mobility barriers. We find a strong association between reduced mental health care provider spatial-social accessibility and heightened suicide risk. Using a machine learning approach to condition on a host of 22 contextual factors known to be implicated in suicide (e.g., race, education, divorce, gun shop prevalence), we find that in locales where individuals seeking care can access fewer mental health care providers, already more likely to be saturated by demand, suicide risk is increased (3.2% for each reduced SD of psychiatrist accessibility; 2.3% for psychotherapists). Additionally, we observe that local spatial-social accessibility inequalities are associated with further heightened risk of suicide, underscoring the need for research to account for the highly localized barriers preventing many Americans from accessing needed mental health services.