Chronic liver diseases impose a considerable global public health burden, yet available treatment options remain largely inadequate. The gut microbiota exerts a key modulatory effect on liver disease pathogenesis via the gut-liver axis. Among them, Lachnospiraceae, a dominant bacterial family in the healthy adult gut, has drawn growing interest in recent years. Lachnospiraceae exert protective functions by producing short-chain fatty acids, participating in secondary bile acid conversion, and synthesizing active metabolites such as N-acetyl-glutamic acid, thereby maintaining intestinal barrier integrity and regulating host metabolic and immune homeostasis. Extensive evidence indicates that in cirrhosis, alcohol-associated liver disease, and metabolic dysfunction-associated steatotic liver disease, Lachnospiraceae abundance is consistently and significantly reduced, and this decrease is closely correlated with disease severity and adverse prognosis. In hepatocellular carcinoma, however, different members of Lachnospiraceae exhibit functional divergence, with some butyrate-producing genera decreasing while other subgroups may become enriched and influence the tumor immune microenvironment. Live biotherapeutic products based on Lachnospiraceae have achieved clinical breakthroughs in recurrent Clostridioides difficile infection and metabolic syndrome, providing important references for their translational application in liver diseases. This review systematically synthesizes the abundance changes and mechanisms of Lachnospiraceae across major liver diseases, evaluates their biomarker and therapeutic target potential, and seeks to provide fresh perspectives for precision microbiome-modulating strategies in chronic liver disease management.