Patients with aortic stenosis who undergo transcatheter aortic valve replacement/transcatheter aortic valve implantation (TAVR/TAVI) experience a high incidence of pre-existing atrial fibrillation (pre-AF) and new-onset atrial fibrillation (NOAF) post-operatively. This systematic review and meta-analysis aimed to update current evidence concerning the incidence of 30-day mortality, stroke, acute kidney injury (AKI), length of stay (LOS), and early/late bleeding in patients with NOAF or pre-AF who undergo TAVR/TAVI. PubMed, Google Scholar, JSTOR, Cochrane Library, and Web of Science were searched for studies published between January 2012 and December 2020 reporting the association between NOAF/pre-AF and clinical complications after TAVR/TAVI. A total of 15 studies including 158,220 adult patients with TAVI/TAVR and NOAF or pre-AF were identified. Compared to patients in sinus rhythm, patients who developed NOAF had a higher risk of 30-day mortality, AKI, early bleeding events, extended LOS, and stroke after TAVR/TAVI (odds ratio [OR]: 3.18 [95% confidence interval [CI] 1.58, 6.40]) (OR: 3.83 [95% CI 1.18, 12.42]) (OR: 1.70 [95% CI 1.05, 2.74]) (OR: 13.96 [95% CI, 6.41, 30.40]) (OR: 2.51 [95% CI 1.59, 3.97], respectively). Compared to patients in sinus rhythm, patients with pre-AF had a higher risk of AKI and early bleeding episodes after TAVR/TAVI (OR: 2.43 [95% CI 1.10, 5.35]) (OR: 17.41 [95% CI 6.49, 46.68], respectively). Atrial fibrillation is associated with a higher risk of all primary and secondary outcomes. Specifically, NOAF but not pre-AF is associated with a higher risk of 30-day mortality, stroke, and extended LOS after TAVR/TAVI.