Adherence to antiretroviral therapy (ART) is necessary for the improvement of the health of patients and for public health. We sought to determine the comparative effectiveness of different interventions for improving ART adherence in HIV-infected people living in Africa. We searched for randomised trials of interventions to promote antiretroviral adherence within adults in Africa. We searched AMED, CINAHL, Embase, Medline (via PubMed), and ClinicalTrials.gov from inception to Oct 31, 2014, with the terms "HIV", "ART", "adherence", and "Africa". We created a network of the interventions by pooling the published and individual patients' data for comparable treatments and comparing them across the individual interventions with Bayesian network meta-analyses. The primary outcome was adherence defined as the proportion of patients meeting trial defined criteria; the secondary endpoint was viral suppression. We obtained data for 14 randomised controlled trials, with 7110 patients. Interventions included daily and weekly short message service (SMS; text message) messaging, calendars, peer supporters, alarms, counselling, and basic and enhanced standard of care (SOC). Compared with SOC, we found distinguishable improvement in self-reported adherence with enhanced SOC (odds ratio [OR] 1·46, 95% credibility interval [CrI] 1·06-1·98), weekly SMS messages (1·65, 1·25-2·18), counselling and SMS combined (2·07, 1·22-3·53), and treatment supporters (1·83, 1·36-2·45). We found no compelling evidence for the remaining interventions. Results were similar when using viral suppression as an outcome, although the network contained less evidence than that for adherence. Treatment supporters with enhanced SOC (1·46, 1·09-1·97) and weekly SMS messages (1·55, 1·01-2·38) were significantly better than basic SOC. Several recommendations for improving adherence are unsupported by the available evidence. These findings can inform future intervention choices for improving ART adherence in low-income settings. None.