Eliciting HIV-1 expression from latently infected CD4 + T cells allows these rare reservoir cells to become targets of the immune system and may also result in death of reservoir cells via virus-induced cytopathy. We asked whether administration of recombinant interleukin-2 (rIL-2) to people with HIV-1 (PWH) on antiretroviral therapy (ART) would induce HIV-1 replication and activate cellular immunity. Nine men with ART-suppressed HIV-1 completed a single 4-day cycle of rIL-2 administration. Plasma HIV-1 RNA levels rose from <20 copies per milliliter at entry to a mean of 301 copies per milliliter at day 7 (an average increase of 0.82 log 10 ; P = 0.008). In addition, we observed robust natural killer and T cell activation, with a modest increase in regulatory T cell–like cells. Thus, rIL-2 appears to be one of the most potent latency-reversing agents tested in PWH on ART.