Gather the ingredients.

Bring a large pot of lightly salted water to a boil. Cook corn in boiling water for 7 to 10 minutes, or until desired tenderness. Drain, cool, and cut kernels off the cob with a sharp knife.

Combine corn, tomatoes, onion, and basil in a large bowl. Whisk together olive oil and vinegar; season with salt and pepper. Pour vinaigrette over corn mixture and toss to coat. Cover and refrigerate until ready to serve.