An efficient and unprecedented S-glycosylation reaction of benzo-2,1,3-thiadiazole at the C-5-position using a Pd-G₃ Xantphos palladacycle precatalyst has been described. This methodology showed a high functional group tolerance to the electrophilic partner and can be successfully applied to a variety of β-mono- and di-thiosugar derivatives. A series of thioglycoside derivatives from benzo-2,1,3-thiadiazole were prepared in good to excellent yields under mild and operationally simple reaction conditions.