Ending the COVID-19 pandemic will require long-lasting immunity to SARS-CoV-2. Here, we evaluate 254 COVID-19 patients longitudinally up to 8 months and find broad-based durable immune responses. Neutralizing and SARS-CoV-2 spike-binding antibodies show biphasic decay with an extended half-life of >200 days, suggesting generation of longer-lived plasma cells. SARS-CoV-2 infection also increases antibody titers against SARS-CoV-1 and common beta-coronaviruses. In addition, spike-specific IgG+ memory B cells persist, which bodes well for a rapid antibody response to virus re-exposure or vaccination. Virus-specific CD4+ and CD8+ T cells are multifunctional and are maintained with an estimated half-life of 200 days. Interestingly, CD4+ T-cell responses equally target several SARS-CoV-2 proteins, whereas CD8+ T-cell responses preferentially target the nucleoprotein, highlighting the potential importance of nucleoprotein inclusion in future vaccines. Taken together, these findings suggest that broad and effective immunity may persist over the long term in patients cured of COVID-19.