Protein post-translational modifications (PTMs) are critical for modulating protein structure and function. Among these, lysine lactylation (Kla) has garnered significant attention in recent years as a newly discovered PTM. Although Kla has been thoroughly investigated in eukaryotic systems, its study in prokaryotes, especially bacteria, remains comparatively limited. Emerging research highlights that bacterial Kla, operating through dynamic modification mechanisms, is pivotal in processes such as growth and metabolism, virulence control, pathogenicity, and host-pathogen interactions. This article provides a comprehensive overview of the latest progress in bacterial Kla research, emphasizing its historical discovery, distinct modification features, and underlying molecular regulatory mechanisms. We further explore the regulatory roles of this modification in bacterial physiological processes and pathogenesis, concluding with a discussion of current research challenges and prospective future developments.