What terminal is Frontier Airlines At ORD. Frontier Airlines passengers enjoy a comfortable environment at O’Hare’s Terminal 5. Its modern amenities, efficient design, and diversity of services appeal to both leisure and business travelers. Although it may appear to be apart from the other terminals, its international orientation creates a distinct and energetic ambiance. Terminal 5 is continuing to improve the travel experience by adding more stores and dining options. Passengers flying domestically or internationally can expect a seamless ride while departing or arriving at this terminal, making it a popular choice for those flying with Frontier Airlines at ORD.