Objectives: 1) To explore the role of ethnicity in receiving Cognitive Behavioural Therapy (CBT) for people with psychosis or bipolar disorder whilst adjusting for differences in risk profiles and symptom severity. 2) To assess whether context of treatment (inpatient versus community) impacts on the relationship between ethnicity and access to CBT.Design: Cohort study of case-register data from one catchment area (January 2007 to July 2017).Setting: A large secondary care provider serving an ethnically-diverse population in London.Participants: Data extracted for 30,497 records of people who had diagnoses of bipolar disorder (ICD Code F30-1) or psychosis (F20-F29 excluding F21). Exclusion criteria were: <15 years old, missing data, and not self-defining as belonging to one of the larger ethnic groups. The sample (N=20010) comprised the following ethnic groups: White British, n=10393; Black Caribbean, n=5481, Black African, n=2817; Irish, n= 570; and ‘South Asian’people (consisting of Indian, Pakistani, and Bangladeshi people) n=749.Outcome Assessments: Odds ratios for receipt of CBT (single session or full course) as determined via multivariable logistic regression analyses.Results: In models adjusted for risk and severity variables, in comparison to White British people; Black African people were less likely to receive a single session of CBT (OR 0.73, CI 0.66 to 0.82, p<.001); Black Caribbean people were less likely to receive a minimum of 16-sessions of CBT (OR 0.83, CI 0.71 to 0.98, p=.03); Black African and Black Caribbean people were significantly less likely to receive CBT whilst inpatients (respectively OR 0.76, CI 0.65 to 0.89, p=.001; OR 0.83, CI 0.73 to 0.94, p=.003).Conclusions: This study highlights disparity in receipt of CBT from a large provider of secondary care in London for Black African and Caribbean people and that the context of therapy (inpatient versus community settings) has a relationship with disparity in access to treatment.