NF‐κB is a transcription factor activated by various cytokines and cellular stress. Upon activation, NF‐κB induces expression of a number of genes that regulate immunity, inflammation, cell survival, cell proliferation, embryonic development, and carcinogenesis. NF‐κB‐induced gene expression is mainly associated with inflammatory response in immune cells including hepatic macrophages, whereas NF‐κB plays very important roles in antiapoptotic gene expression and cell survival in hepatocytes. In hepatic stellate cells, NF‐κB regulates cellular activation, survival, and fibrogenesis. We will summarize the signaling pathway and the functions of NF‐κB in various liver diseases, such as TNF‐induced liver injury, ischemia‐reperfusion injury, regeneration, liver fibrosis, hepatocarcinogenesis, and steatohepatitis.