Objectives Systemic inflammation is increasingly being recognised as a possible mechanism for acute arterial thrombotic events, including acute coronary syndrome (ACS). Despite this, there is conflicting data on the risk of ACS in patients with inflammatory bowel disease (IBD). We performed a contemporary systematic review and meta-analysis to identify the risk of ACS in patients with IBD. Methods PubMed, MEDLINE, EMBASE, CENTRAL and Web of Science were searched up to 27 October 2022. Multivariable-adjusted or propensity matched studies with a non-IBD control cohort were included. HRs were pooled using a random-effects model. Subgroup and sensitivity analyses were conducted in order to explore sources of heterogeneity. Results Twelve retrospective cohort studies were included (225 248 IBD patients). Patients with IBD were associated with an increased risk of ACS in both adjusted (HR 1.23; 95% CI 1.08 to 1.41) and unadjusted analyses (HR 1.50; 95% CI 1.16 to 1.92). Substantial heterogeneity was observed (i2=88, p=0.002 and i2=98%, p=0.002, respectively). Subgroup analysis of age revealed a greater association of ACS in IBD patients <40 years of age (relative HR 1.50; 95 CI 1.15 to 1.96). Conclusion Patients with IBD demonstrated an independently increased risk of ACS. Prospective studies are required to explore the relationship with disease activity and duration, concomitant medication use and angiographic characteristics and outcomes.