Suboptimal HIV/STI testing uptake has a profound impact on morbidity and mortality. Incentives have been effective in other areas of medicine and may improve HIV/STI testing uptake rates. This study reviewed the effects of incentives on HIV/STI testing uptake. A systematic search of seven databases was undertaken. Testing uptake was defined as test implementation and/or test result retrieval. Incentives were defined as monetary or non-monetary rewards or free-of-charge testing vouchers. Seven studies were included. All seven studies demonstrated higher rates of uptake in an incentivized group. Incentives offered at a non-clinical setting demonstrated more significant differences in uptake rates compared to incentives offered at a clinical setting. Incentivizing HIV/STI testing uptake, especially testing at a non-clinical setting, may be a useful tool to modify health behavior. Further research is needed to understand how incentives could be an effective component within a comprehensive HIV/STI control strategy.