Flight
Flying into Cancun - Cancun Airport does have direct flights and is 4.5 hours away from Bacalar. You can either rent a car, take the Mayan Train, or rent a shuttle. Shuttles are a great option in Bacalar for larger groups traveling together when booked in advanced.
Flight
Flying into Tulum - Tulum airport is 2.5 hours away from Bacalar. It is a newer airport, and due to this flights are currently cheaper. From Tulum, you can either rent a car, take the Mayan Train, or book a shuttle.
Flight
Flying into Chetumal - no direct flights exist to Bacalar. Chetumal is the closest airport, 40 minutes away. There would be one stop in Mexico City. Upon arrival at Chetumal Airport, Bacalar is a 30 minute taxi away.
Travel Note
By Train: The Mayan Train goes directly to Bacalar from the Cancun & Tulum Airports. As of now, it departs twice a day. Tickets can be booked a few weeks in advance at https://www.turitren.mx/en/boletos-tren-maya By Shuttle: Shuttles can be booked through a number of companies online. Booking shuttles with larger parties ahead of time is recommended if choosing this option. By Car: Driving to Bacalar is a straight shot and we personally had a wonderful experience with Easy Way Rent A Car Rentals next to the Cancun Airport that offered free pickup/drop-off to & from the airport.