Successful sperm cell delivery to the embryo sac is mediated by pollen tube growth in higher plants. The molecular mechanisms underlying pollen germination and tube growth in crop plants remain highly unclear, although these mechanisms are crucial to plant reproduction and seed formation. By screening pollen-specific gene mutants in rice (Oryza sativa), we identified a T-DNA insertional mutant of Germinating modulator of rice pollen (GORI) that showed one-to-one segregation ratio for wild type (WT) to heterozygotes. GORI encodes a seven-WD40 motif protein that is homologous to JINGUBANG/REN4 in Arabidopsis. GORI is specifically expressed in rice pollen, and its protein is localized in the nucleus, cytosol, and plasma membrane. Furthermore, a homozygous mutant, gori-2, created through CRISPR-Cas9 clearly exhibited male sterility with disruption of pollen tube germination and elongation. The germinated pollen tube of gori-2 exhibited decreased actin filament and altered pectin distribution. Transcriptome analysis revealed that 852 pollen-specific genes were downregulated in gori-2 compared with the WT, and gene ontology enrichment analysis indicated that these genes are strongly associated with cell wall modification and clathrin coat assembly. Based on the molecular features of GORI, phenotypical observation of the gori mutant, and its interaction with endocytic proteins and Rac GTPase (ROP), we propose that GORI plays key roles in forming endo/exocytosis complexes that could mediate pollen tube growth in rice.