This study investigates the role of GROWTH REGULATING FACTOR 7 (OsGRF7) in enhancing salt tolerance and grain size in rice. OsGRF7 was found to promote salt tolerance by regulating arbutin (hydroquinone-β-glucopyranoside) metabolism. Overexpression of OsGRF7 increased arbutin content, and exogenous arbutin application rescued the salt-sensitive phenotype of OsGRF7 knockdown and knockout plants. OsGRF7 directly activated the expression of arbutin biosynthesis genes, URIDINE DIPHOSPHATE GLYCOSYLTRANSFERASE 1 (OsUGT1) and OsUGT5, and knockout of these genes reduced rice arbutin content, salt tolerance, and grain size. Additionally, OsGRF7 degradation through its interaction with F-BOX AND OTHER DOMAINS CONTAINING PROTEIN 13 (OsFB013) reduced rice salt tolerance and grain size. These findings highlight the underexplored role of OsGRF7 in modulating rice arbutin metabolism, salt stress response, and grain size, with potential applications in rice breeding.This study investigates the role of GROWTH REGULATING FACTOR 7 (OsGRF7) in enhancing salt tolerance and grain size in rice. OsGRF7 was found to promote salt tolerance by regulating arbutin (hydroquinone-β-glucopyranoside) metabolism. Overexpression of OsGRF7 increased arbutin content, and exogenous arbutin application rescued the salt-sensitive phenotype of OsGRF7 knockdown and knockout plants. OsGRF7 directly activated the expression of arbutin biosynthesis genes, URIDINE DIPHOSPHATE GLYCOSYLTRANSFERASE 1 (OsUGT1) and OsUGT5, and knockout of these genes reduced rice arbutin content, salt tolerance, and grain size. Additionally, OsGRF7 degradation through its interaction with F-BOX AND OTHER DOMAINS CONTAINING PROTEIN 13 (OsFB013) reduced rice salt tolerance and grain size. These findings highlight the underexplored role of OsGRF7 in modulating rice arbutin metabolism, salt stress response, and grain size, with potential applications in rice breeding.