IntroductionGlobally, young gay, bisexual and other men who have sex with men (gbMSM) continue to experience disproportionately high rates of HIV and other sexually transmitted and blood‐borne infections (STBBIs). As such, there are strong public health imperatives to evaluate innovative prevention, treatment and care interventions, including online interventions. This study reviewed and assessed the status of published research (e.g. effectiveness; acceptability; differential effects across subgroups) involving online interventions that address HIV/STBBIs among young gbMSM.MethodsWe searched Medline, Embase, PsycINFO, CINAHL, and Google Scholar to identify relevant English‐language publications from inception to November 2016. Studies that assessed an online intervention regarding the prevention, care, or treatment of HIV/STBBIs were included. Studies with <50% gbMSM or with a mean age ≥30 years were excluded.ResultsOf the 3465 articles screened, 17 studies met inclusion criteria. Sixteen studies assessed interventions at the “proof‐of‐concept” phase, while one study assessed an intervention in the dissemination phase. All of the studies focused on behavioural or knowledge outcomes at the individual level (e.g. condom use, testing behaviour), and all but one reported a statistically significant effect on ≥1 primary outcomes. Twelve studies described theory‐based interventions. Twelve were conducted in the United States, with study samples focusing mainly on White, African‐American and/or Latino populations; the remaining were conducted in Hong Kong, Peru, China, and Thailand. Thirteen studies included gay and bisexual men; four studies did not assess sexual identity. Two studies reported including both HIV+ and HIV− participants, and all but one study included one or more measure of socio‐economic status. Few studies reported on the differential intervention effects by socio‐economic status, sexual identity, race or serostatus.ConclusionWhile online interventions show promise at addressing HIV/STBBI among young gbMSM, to date, little emphasis has been placed on assessing: (i) potential differential effects of interventions across subgroups of young gbMSM; (ii) effectiveness studies of interventions in the dissemination phase; and (iii) on some “key” populations of young gbMSM (e.g. those who are: transgender, from low‐income settings and/or HIV positive). Future research that unpacks the potentially distinctive experiences of particular subgroups with “real world” interventions is needed.