Gametogenesis is essential for malaria parasite transmission, but the molecular mechanism of this process remains to be refined. Here, we identified a G-protein-coupled receptor 180 (GPR180) that plays a critical role in signal transduction during gametogenesis in Plasmodium. In the rodent parasite P. berghei, PbGPR180 was expressed during asexual and sexual development, with more prominent expression in gametocytes and ookinetes. While PbGPR180 was predominantly localized to cytoplasmic puncta in asexual stages and gametocytes, it became associated with the plasma membrane in female gametes and ookinetes. Knockout of pbgpr180 (Δpbgpr180) had no noticeable effect on asexual development or gametocytogenesis but impaired gamete formation and reduced transmission of the parasites to mosquitoes. Transcriptome analysis of the Δpbgpr180 gametocytes revealed a large proportion of the dysregulated genes with assigned functions in cyclic nucleotide signaling transduction, especially the cGMP-PKG-Ca2+ signaling cascade. Deletion of pbgpr180 resulted in a delay and reduction in cytosolic Ca2+ mobilization during the induction of gametogenesis. In addition, the intracellular cGMP level was significantly reduced in the Δpbgpr180 gametocytes, suggesting that PbGPR180 functions upstream of the cGMP-PKG-Ca2+ signaling pathway. In line with this function, PbGPR180 protein was found to interact with several transmembrane transporter proteins and a small GTPase, Rab6, in activated gametocytes. Allele replacement of pbgpr180 with the P. vivax ortholog pvgpr180 showed equal competence of the transgenic parasite in sexual development, suggesting functional conservation of this gene in Plasmodium spp . These results indicate that GPR180 is involved in cGMP-PKG-Ca2+ signal transduction to regulate gametogenesis in malaria parasites.