Lamb meat, valued for its nutritional quality and sensory attributes, is susceptible to microbial spoilage during refrigeration. Although modified atmosphere packaging (MAP) can extend its shelf life, its effects on microbial succession in lamb meat are poorly defined. This study examined bacterial community dynamics in MAP (80% O₂/20% CO₂) chilled lamb meat over 35 days using high-throughput 16S rRNA gene sequencing. The bacterial composition, alpha diversity (Shannon, Chao1, Faith’s phylogenetic diversity, Pielou’s evenness), and beta diversity (Jaccard, Bray-Curtis, ANOSIM) were analysed using QIIME 2. Principal Coordinate Analysis revealed distinct successional shifts (ANOSIM R, P < 0.01) in the bacterial community over time. The Chao1 richness increased, Shannon diversity remained stable, while Faith’s phylogenetic diversity and evenness decreased significantly (P < 0.05), reflecting the selective MAP and low-temperature pressure on bacterial community dynamics. While Proteobacteria and Firmicutes dominated throughout storage, increased dominance of spoilage-associated taxa, including Carnobacterium divergens, Pseudomonas fragi, and Brochothrix thermosphacta, occurred after Day 28. The dominance of these groups highlights their role in shelf-life limitation. These results provide detailed insights into microbial succession in MAP lamb meat with potential implications for the meat’s shelf life and for future preservation strategies.