Background: Postpartum anemia (PPA) is defined as a hemoglobin concentration below 11 g/dL within the first week following delivery, or below 12 g/dL at eight weeks postpartum. It constitutes a major yet under-addressed public health burden in sub-Saharan Africa, contributing substantially to maternal morbidity and mortality. In Ethiopia, anemia prevalence among women of reproductive age has been increasing despite national nutrition strategies, yet aggregated, nationally representative data on PPA remain scarce. This systematic review and meta-analysis aimed to estimate the pooled prevalence of anemia among postpartum mothers attending public health facilities in Ethiopia and to identify significantly associated factors. Methods: A comprehensive literature search was conducted across PubMed/MEDLINE, Cochrane Library, Google Scholar, African Journals Online (AJOL), and HINARI from inception to December 2024. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines were followed. Observational studies (cross-sectional, cohort) conducted in public health facilities in Ethiopia, reporting hemoglobin-confirmed PPA prevalence and/or associated factors, were included. Two reviewers independently performed study selection, data extraction, and quality assessment using a modified Newcastle-Ottawa Scale (NOS) adapted for cross-sectional studies. Heterogeneity was quantified using the Cochran Q statistic and I-squared index. Pooled prevalence estimates and odds ratios were computed using a random-effects (DerSimonian-Laird) model with 95% confidence intervals. Subgroup analyses were performed by geographic region (Eastern vs. Western/Central Ethiopia), study period, and facility type. Publication bias was assessed via Egger weighted regression test and funnel plot asymmetry. Results: Six primary studies, encompassing 2,819 postpartum mothers, fulfilled the eligibility criteria and were included in the meta-analysis. The pooled prevalence of anemia among postpartum mothers in Ethiopian public health facilities was 35.4% (95% CI: 27.6-43.6%; I2 = 89.2%), classified as a severe public health problem per WHO thresholds. Subgroup analysis revealed higher prevalence in Eastern Ethiopia (Dire Dawa and Harari regions: 27.5%) compared to Western/Central Ethiopia (Gondar and Debre Markos: 24.3-47.1%), though marked heterogeneity was observed. Factors significantly associated with higher odds of PPA included: fewer than four antenatal care (ANC) visits (pooled OR = 2.72; 95% CI: 2.14-3.30), history of postpartum hemorrhage (OR = 2.49; 95% CI: 1.08-3.98), cesarean section delivery (OR = 4.04; 95% CI: 3.43-4.67), instrumental delivery forceps/vacuum (OR = 3.96; 95% CI: 2.99-4.95), poor adherence to iron and folic acid (IFA) supplementation (OR = 2.80; 95% CI: 2.31-3.30), low pre-delivery hemoglobin < 11 g/dL (OR = 4.20; 95% CI: 1.77-6.67), low dietary diversity (OR = 4.20; 95% CI: 1.77-6.67), and lack of formal education (OR = 3.50; 95% CI: 2.64-4.41). Conclusions: Nearly one in three postpartum mothers attending public health facilities in Ethiopia is anemic, constituting a severe public health emergency. The burden is driven by modifiable clinical and behavioral factors particularly inadequate ANC utilization, poor IFA adherence, hemorrhagic complications, and nutritional deficiencies as well as structural determinants including low educational attainment. Evidence-based, multi-sectoral interventions are urgently needed, including strengthening ANC quality and coverage, universal IFA supplementation monitoring, active postpartum hemorrhage management, and targeted nutritional counseling. Policy frameworks must address regional disparities and integrate anemia screening into routine postpartum care protocols.