The tumor microenvironment was once considered to have little effect on tumor growth and invasion.However, it has now been recognized that it plays an indispensable role in tumor development. One of the commoncharacteristics of tumors is hypoxia, which is also one of the representative characteristics of the tumor microenvironment.Hypoxia leads to an increase in extracellular hydrogen ion concentrations, a decrease in pH (acidosis), and the formationof a specific acidic microenvironment. The acidic microenvironment plays an important role not only in the proliferation,migration, invasion, metastasis and treatment of cancer cells, but also in the function of immune cells, vascular cells andother stromal cells. However, the molecular mechanism through which tumor cells perceive and respond to acidic pH intheir microenvironment remains unclear. Previous studies have shown that some receptors and ion channel families can helpcells to perceive acidosis. As a G-protein coupled receptor (GPCR), ovarian cancer G-protein coupled receptor 1 (OGR1)is activated by acidosis and mediates several downstream G-protein signal transduction pathways. It can not only regulatemetastasis and proliferation in cancer cells, but also plays an important role in the function of immune cells, inflammationand angiogenesis. In the current review, the effects of OGR1 in tumorigenesis, the tumor microenvironment, the immuneresponse and angiogenesis are discussed. The development of small molecule regulators targeting GPCRs has become an areaof active research in recent years. Studying the interaction between OGR1 and the tumor microenvironment will provide new strategies for cancer treatment and chemoprevention.