〔Abstract〕 Objective To investigate the distribution characteristics and correlation of paired oral and esophageal microbiota in patients with esophageal squamous cell carcinoma (ESCC). Methods A total of 46 pathologically confirmed ESCC patients were enrolled, and oral swabs and cancerous tissue samples were collected. The microbial composition was analyzed using 16S rRNA gene sequencing, and bioinformatics methods were employed to compare the microbiota diversity, compositional differences, and correlations between the two sites. Results The Alpha diversity of the oral microbiota in ESCC patients was significantly higher than that of their esophageal microbiota, though the overall community structure was similar between the two sites. LEfSe analysis revealed that Spirochaetes, Prevotella, Catonella, Enterococcus, Fusobacterium periodonticum, Veillonella parvula, Capnocytophaga sputigena, and Neisseria subflava were significantly enriched in ESCC tumor tissues. In contrast, Actinobacteria, Proteobacteria, Streptococcus, Neisseria, Haemophilus, Streptococcus mitis, Haemophilus parainfluenzae, Porphyromonas gingivalis, Haemophilus haemolyticus, and Prevotella tannerae were significantly enriched in the oral cavity. Correlation analysis demonstrated significant associations between the two sites at taxonomic levels such as Spirochaetes, Treponema, Granulicatella elegans, Neisseria macacae, Treponema amylovorum, Fusobacterium periodonticum, and Neisseria meningitidis (P<0.05). Conclusion The oral and esophageal microbiota in ESCC patients exhibit both distinct differences and similarities. Oral microbiota may influence the esophageal microenvironment through migration or local immune modulation.