Abstract: Fibrosis, caused by excessive production and deposition as well as reduction of the extracellular matrix, is a common occurrence during aging of many substantial organs. Under a pathological state, fibrosis can cause damage to organ structure and function, thereby resulting in organ failure in severe cases. Since 2012, advancement of high-throughput technology has led to exploration of many circular RNAs (circRNAs). These competitive endogenous RNAs play a complicated but crucial role in various processes of cell signal transduction and human diseases. To date, numerous researches have shown that circRNAs can either inhibit or promote fibrosis in many organs, including the heart, kidney, lung, and liver. In this review, we systematically review the current progress for the role of circRNA in fibrosis, with the aim of providing a theoretical basis for future development of targeted therapies against the disease.