A lorry carrying 1,137kg (2,506 pounds) of cocaine was intercepted in the eastern town of Kidira, which is near the border with Mali.
The drug had been concealed in packets and placed in bags at the bottom of the lorry, which had arrived from a neighbouring country that authorities failed to name.
They said the consignment was valued at 90bn CFA francs ($146m; £117m).
Large drug hauls have become more common in Senegal.
Last November, the navy seized three tonnes of cocaine from a ship off the country's coast, marking one of the navy's largest drug hauls.
The region is a transit point for Latin American cartels trafficking drugs to Europe and elsewhere.