Heat olive oil in a large skillet over medium-high heat. Add ground turkey and cook, breaking it up with a spoon, until no longer pink. Drain any excess fat.
Stir in the chopped onion and minced garlic. Cook until the onion is softened, about 3-5 minutes.
Add taco seasoning and water. Bring to a simmer and cook for 5-7 minutes, or until the liquid has mostly evaporated and the turkey is well coated.
Warm taco shells according to package directions.
Fill each taco shell with the ground turkey mixture. Serve with your favorite toppings.
Notes
Adjust the amount of taco seasoning to your taste preference.
For a spicier kick, add a pinch of cayenne pepper or a chopped jalapeño with the onion.
Leftover turkey mixture can be stored in an airtight container in the refrigerator for up to 3 days.