Activating transcription factor 3 (ATF3) belongs to the transcription factor ATF/CREB family and is a stress-induced adaptive response gene. ATF3 is involved in the regulation of various cell activities to adapt to the changes in intracellular and extracellular environments. Recent studies have shown that ATF3 plays an important role in the development and progression of various chronic liver diseases, including nonalcoholic fatty liver disease, liver fibrosis, and liver cancer, by regulating gluconeogenesis, lipid metabolism, and immune function. This article reviews the mechanism of action of ATF3 in chronic liver diseases.