Sugar transport is critical for normal plant development and stress responses. However, functional evidence for the roles of monosaccharide transporters in rice (Oryza sativa) has not previously been presented. In this study, reversed genetics was used to identify OsGMST1 as a member of the monosaccharide transporter family in rice. The predicted 481 amino acid protein has the typical features of a sugar transporter in the plastid glucose transporter subfamily consistent with reduced monosaccharide accumulation in plants with reduced OsGMST1 expression. OsGMST1-green fluorescent protein is localized to the Golgi apparatus. OsGMST1 expression is induced by salt treatment and reduced expression confers hypersensitivity to salt stress in rice. OsGMST1 may play a direct or an indirect role in tolerance to salt stress in rice.