Objective: To investigate the association between deprivation and COVID-19 outcomes in Italy during pre-lockdown, lockdown and post-lockdown periods.Design: Retrospective cohort study.Setting: All municipalities in Italy with less than 50,000 population.Participants: 38,534,169 citizens and 222,875 COVID-19 cases reported to the Italian epidemiological surveillance were assigned to quintiles based on the deprivation index of their municipality of residence.Interventions: The COVID-19 pandemic during pre-lockdown, lockdown and post-lockdown from the 20th of February to the 15th of October of 2020.Main outcome measures: Multilevel negative binomial regression models, adjusting for age, sex, population-density and region of residence were conducted to evaluate the association between deprivation and COVID-19 incidence, case-hospitalisation rate and case-fatality. The association measure was the rate ratio.Results: During pre-lockdown, lockdown and post-lockdown, the incidence rate ratios (IRR) with 95% confidence interval (CI) in the most deprived quintile with respect to the least deprived quintile were 1.17 (95% CI 0.98 to 1.41), 1.14 (1.03 to 1.27) and 1.47 (1.32 to 1.63), respectively. In those three periods, the case-hospitalization IRR were 0.68 (0.51 to 0.92), 0.89 (0.72 to 1.11) and 0.99 (0.81 to 1.22) and the case-fatality IRR were 0.92 (0.75 to 1.13), 0.95 (0.85 to 1.07) and 1.02 (0.73 to 1.41), respectively.Conclusions: During lockdown and post-lockdown, but not during pre-lockdown, a higher incidence of cases was observed in the most deprived municipalities compared with the least deprived ones. No differences in case-hospitalisation and case-fatality according to deprivation were observed in any period under study.