Background Increasing demands of COVID-19 on the healthcare system necessitated redeployment of HCWs outside their routine specialties. Previous studies, highlighting ethnic and occupational inequalities in redeployment, are limited by small cohorts with limited ethnic diversity. Aims To assess how ethnicity, migration status, and occupation are associated with HCWs redeployment experiences during COVID-19 in a nationwide ethnically diverse sample. Methods We conducted a cross-sectional analysis using data from the nationwide United Kingdom Research Study into Ethnicity And COVID-19 outcomes in Healthcare workers (UK-REACH) cohort study. We used logistic regression to examine associations of ethnicity, migration status, and occupation with redeployment experiences of HCWs, including provision of training and supervision, patient contact during redeployment and interaction with COVID-19 patients. Results Of the 10,889 HCWs included, 20.4% reported being redeployed during the first UK national lockdown in March 2020. Those in nursing roles (Odds Ratio (OR) 1.22, 95% Confidence Interval (CI) 1.04 to 1.42, p=0.009) (compared to medical roles) had higher likelihood of being redeployed as did migrants compared to those born in the UK (OR 1.26, 95% CI 1.06 to 1.49, p=0.01) (in a subcohort of HCWs on the agenda for change (AfC) pay scales). Asian HCWs were less likely to report receiving training (OR 0.66, 95% CI 0.50 to 0.88, p=0.005) and Black HCWs (OR 2.02, 95% CI 1.14 to 3.57, p=0.02) were more likely to report receiving supervision, compared to White colleagues. Finally, redeployed Black (OR 1.33, 95% CI 1.07 to 1.66, p=0.009) and Asian HCWs (OR 1.30, 95% CI 1.14 to 1.48, p<0.001) were more likely to report face-to-face interaction with COVID-19 patients than White HCWs. Conclusions Our findings highlight disparities in HCWs redeployment experiences by ethnicity, migration, and job role which are potentially related to structural inequities in healthcare. For future emergencies, redeployment should be contingent upon risk assessments, accompanied by training and supervision tailored to individual HCWs experience and skillset.