Bring a large pot of lightly salted water to a boil. Cook tortellini in the boiling water, stirring occasionally until pasta floats to the surface, about 5 minutes.
Drain.
Mix tortellini, feta cheese, tomatoes, olives, walnuts, green onions, and garlic together in a large bowl.
Whisk vinegar, olive oil, and basil together in a separate small bowl.
Pour dressing over tortellini mixture; toss to coat.
Sprinkle with salt. Chill in refrigerator for 1 hour before serving.
