Use a microplane, or grater, to zest the orange, making sure to grate only the orange rind and not the white pith, which can be bitter. Once the zest has been removed, juice the orange using a citrus press or reamer.
Combine the fresh orange juice, zest, apple cider vinegar, garlic, honey and salt in a high-speed blender, and blend until smooth. Add in the olive oil, and blend again until completely emulsified.
Adjust sweetness to taste, and allow to chill for 4 hours before serving.