What Terminal is Frontier Airlines At BOS? Frontier Airlines serves from Terminal E of Boston Logan International Airport (BOS). Terminal E is largely utilized for foreign flights, but it also serves some domestic airlines, notably Frontier. The terminal is outfitted with check-in counters, security checks, and gates tailored to Frontier’s operations. It provides a variety of amenities, including as food options, stores, and services, to help travelers travel more conveniently. If you’re flying Frontier, make sure to confirm your terminal on the day of your flight, as gate assignments sometimes vary.