Preheat an outdoor grill to high heat and lightly oil grate.
Cut zucchini into thin lengthwise planks; brush with olive oil and season with salt and black pepper. Arrange on grate without crowding.
Grill until tender and lightly charred, 2 to 3 minutes per side. Transfer to a rimmed plate.
Stir together tomatoes, extra-virgin olive oil, apple cider vinegar, and mint in a bowl. Smash some of the tomatoes to release their juices. Stir once more and spoon over zucchini.