Heat olive oil in a skillet over medium heat. Add onions and garlic, sauté until softened, about 3 minutes.

Add ground chicken to the skillet. Cook, breaking it apart with a spatula, until no pink remains, about 7 minutes.

Stir in taco seasoning and water. Reduce heat and simmer until most of the liquid has evaporated, about 5 minutes.

Warm tortillas according to package instructions.

Assemble tacos by placing chicken on tortillas, topping with lettuce, tomatoes, cheese, and cilantro. Serve with lime wedges.