We describe the cloning of a novel G protein-coupled receptor, termed ovarian cancer G protein-coupled receptor 1 (OGR1), from an ovarian cancer cell line that maps to chromosome 14q31. The predicted open reading frame of OGR1 encodes a protein of 365 amino acids. OGR1 is expressed as a single 3.0-kb transcript in several tissues, including spleen, testis, small intestine, peripheral blood leukocytes, brain, heart, lung, placenta, and kidney, with no detectable OGR1 expression in thymus, prostate, ovary, colon, liver, skeletal muscle, or pancreas. OGR1 shares strongest homology (49-54%) with the human orphan receptor GPR4. The structural features of OGR1 suggest that the ligand for OGR1 is likely to be a small peptide or a small bioactive molecule.