Greyhound: Greyhound offers daily scheduled coach services between Miami and Key West. The journey takes approximately 4 hours and there are multiple departures throughout the day.
FlixBus: FlixBus also provides scheduled coach services between Miami and Key West. The journey time is comparable to Greyhound and there are various departure times to choose from.
Key West Express: Key West Express offers a non-stop coach service between Miami and Key West. The journey takes about 3 and a half hours, making it slightly faster than other options.
In general, you can book tickets for these coach services online or at designated stations It's always a good idea to compare prices and schedules.