Background: Bacterial vaginosis increases risk of preterm birth and low birthweight, adverse pregnancy outcomes that disproportionately affect low‐ and middle‐income countries (LMICs). Objectives: We aimed to estimate the prevalence of bacterial vaginosis among pregnant women attending antenatal care in LMICs between 2000 and 2020. Search Strategy: We conducted a systematic review of PubMed, Embase and five regional databases. Selection Criteria: We included studies conducted in LMICs and published between 2000 and 2020 in which bacterial vaginosis prevalence was reported among pregnant women attending antenatal care. Data Collection and Analysis: We corrected point estimates and applied random‐effects models to generate pool prevalence estimates. We carried out subgroup analyses by study year, country‐income level, HIV prevalence, sample size, diagnostic method, trimester of pregnancy, presence of symptoms at diagnosis and risk of bias. Main Results: Of 1132 publications, 74 studies met inclusion criteria, contributing 80 data points from 46 661 pregnant women. Overall pooled mean prevalence across LMICs was 15.7%. Regional prevalence ranged from 25.1% in sub‐Saharan Africa to 7.4% in Central and Southern Asia. Prevalence was 33.4% in studies where HIV prevalence was ≥10%, and 6.6% in which HIV prevalence was <10%. The prevalence of bacterial vaginosis among pregnant women who were symptomatic was 24.2% versus 11.8% among those without associated symptoms. Conclusions: Bacterial vaginosis prevalence is high. World Health Organization guidelines recommend screening and treatment for symptomatic pregnant women. This recommendation should be extended to include all pregnant women who have HIV infection. Research is needed to characterise biological mechanisms of bacterial vaginosis that lead to preterm birth and low birthweight, and to investigate antenatal interventions that may better interrupt these pathways.