Objective The objective of this study is to evaluate current evidence for the effectiveness of distance-based interventions to support smoking cessation (SC) or alcohol moderation (AM) among cancer survivors. Secondary, differences in effectiveness are explored regarding multibehaviour interventions versus single-behaviour interventions targeting SC or AM only. Methods A systematic search of PubMed, PsycINFO, Web of Science, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials was conducted. Intervention studies with and without control groups and randomized controlled trials were included. Random effects meta-analyses were conducted for the main outcomes: SC and AM rates at the follow-up closest to 6 months. Using subgroup analyses and meta-regression, effectiveness of single-behaviour versus multibehaviour interventions was evaluated. Results A total of 17 studies with 3796 participants; nine studies on SC only, eight studies on multibehaviour interventions including an SC or AM module, and no studies on AM only were included. All studies had at least some concerns regarding bias. Distance-based SC interventions led to higher cessation rates than control conditions (10 studies, odds ratio [OR] = 1.56; 95% CI, 1.13-2.15, P = .007). Single-behaviour SC interventions reduced smoking rates compared with baseline (risk difference [RD] = 0.29; 95% CI, 0.19-0.39, P < .0001), but multibehaviour interventions did not (RD = 0.13; 95% CI, -0.05 to 0.31, P = 0.15). There was insufficient evidence that distance-based multibehaviour interventions reduced alcohol use compared with controls (three studies, standardized mean difference [SMD] = 0.12; 95% CI, -0.08 to 0.31, P = .24). Conclusions Distance-based SC interventions are effective in supporting SC among cancer survivors. Single-behaviour SC interventions appear more effective than multibehaviour interventions. No evidence was found for the effectiveness of distance-based AM interventions for cancer survivors.