From Geneva airport to Gruyeres was around 4 hours with a lot of intermediate stations using trains mostly.

The route was like Geneva-Lossane-Paleziex-Bulle-Gruyeres.

You have to change train many times but the view is amazing and also you can see smaller cities in between Geneva and Gruyeres.

After you treach Gruyeres the castle is 10' walking from then train station!

As others mentions it all depends where you are staying. But assuming you will be in Geneva, the is a free train shuttle between the airport and the train station (15min ride). At the station, the clerks were very helpful in helping choose the itinerary - scenic vs fast. I took the scenic train. Two perfectly timed connections following Lake Leman then switch back through the mountains. Beautiful! Total travel time about 1h50. And in Gruyeres there is a free 5min shuttle service to the castle, but it is also a lovely walk.

Leah23452015, If you could give the hotel's name and address, I can help you to answer your question. Which hotel?

My question is which Hotel? But anyway from Airport Geneva to Gruyeres there are AT LEAST 90 minutes. I was by car so I hav no idea about the train.

Better there havin a rent car.

Kind regards