what is a good substitute for gruyere cheese?

I can now sleep at night! I found Gruyere in one grocery store here! I squeeled in delight upon seeing it and had to refrain from hugging the charcuterie counter attendant. I also found some French made Comte. I bought both to try them out separately. I can't thank you all enough for all of the recommendations! Now, off I go to construct this heavenly spinach gratin!

Thank you, everybody! I currently live in Spain and have had a hard time, surprisingly, finding Gruyere. I will dig some more to find it but if I can't, I will most definitely follow your recommendations!

Cheeses, generically called Berg Käse (mountain cheeses) produced in the German and Austrian Alps would be a fine substitute. They have a good flavor and the consistency is similar to Gruyere. I don’t know what brands you would find in your region, but I know I’ve seen some sold in the US.

You could probably use an Emmentaler, which is another Swiss cheese.

Gruyere is a type of Swiss cheese (it's actually FROM Switzerland). There are a number of other Swiss cheeses, but none besides Comte comes close to the richness and depth of flavor of Gruyere. Although you could substitute another Swiss, or maybe even another cheese altogether, I'd make it first with the Gruyere. Or you'll never know what you're missing!

Yes, "swiss cheese" is almost the same thing. But what's the difficulty with gruyere?

Swiss cheese could work as a sub