Background & Aims Colonoscopy quality indicators provide measurable assessments of performance, but significant provider-level variations exist. We performed a systematic review and meta-analysis to assess whether endoscopist specialty is associated with adenoma detection rate (ADR) — the primary outcome — or cecal intubation rate, adverse event rates, and post-colonoscopy colorectal cancer rates. Methods We searched EMBASE, Google Scholar, MEDLINE, and the Cochrane Central Registry of Controlled Trials from inception to December 14, 2020. Two reviewers independently screened titles and abstracts. Citations underwent duplicate full-text review, with disagreements resolved by a third reviewer. Data were abstracted in duplicate. The DerSimonian and Laird random effects model was used to calculate pooled odds ratios (ORs) with respective 95% confidence intervals (CIs). Risk of bias was assessed using Risk of Bias in Non-randomised Studies of Interventions. Results Of 11,314 citations, 36 studies representing 3,500,832 colonoscopies were included. Compared with colonoscopies performed by gastroenterologists, those by surgeons were associated with lower ADRs (OR, 0.81; 95% CI, 0.74–0.88) and lower cecal intubation rates (OR, 0.76; 95% CI, 0.63–0.92). Compared with colonoscopies performed by gastroenterologists, those by other (non-gastroenterologist, non-surgeon) endoscopists were associated with lower ADRs (OR, 0.91; 95% CI, 0.87–0.96), higher perforation rates (OR, 3.02; 95% CI, 1.65–5.51), and higher post-colonoscopy colorectal cancer rates (OR, 1.23; 95% CI, 1.14–1.33). Substantial to considerable heterogeneity existed for most analyses, and overall certainty in the evidence was low according to the Grading of Recommendations, Assessment, Development, and Evaluations framework. Conclusion Colonoscopies performed by surgeons or other endoscopists were associated with poorer quality metrics and outcomes compared with those performed by gastroenterologists. Targeted quality improvement efforts may be warranted.