Realdo (Reaud in Occitan, Rêaud in Brigasc, Reaudu in Ligurian) is a hamlet of the municipality of Triora in the province of Imperia. It is located in the Upper Valley of Argentina, bordering the French Roya Valley, and was part of the Piedmont region in the province of Cuneo as a hamlet of Briga Marittima until the Treaty of Paris, after which it became part of Liguria.

It is the Ligurian part of the Brigascan enclave, which is the center of a cross-border area within the region known as the Alps of the Mediterranean.