I will be cruising out of Barcelona. After an all night flight we arrive around noon the day before we sail. Assuming check-in at the hotel is mid afternoon, what do we do with our luggage?
Most hotels I have known let you leave your bag before checkin and have found a new revenue stream by offering early checkin for a price. Or you can lock up at Barcelona Sants train station if you stop there from the airport into the city.
It depends...
1.) Some hotels offer early check-in, alternatively, they offer the possibility to leave your luggage earlier. Note however that this has become less frequent for security reasons (terrorism).
2.) Depending where your hotel is, there are a handful of businesses in the city that will store your luggage for a fee (ie. lockerbarcelona.com)
Oops. Didn't think about the possible security concerns mentioned by Enric. In that case, I'd email the hotel ahead of time to ask. I'm not altering the rest of my post.
Assuming your hotel isn't a little tiny one (occasionally those aren't staffed around the clock), it will certainly have a place to stash your luggage until your room is available. Noon is not terribly early, so you may even be able to get access to your room when you arrive. I've never been asked to pay for that.
Security of your luggage cannot be guaranteed when left in a hotel's storage room, which may have people going in and out and may not always be locked. I don't worry about it because I carry my tablet as well as my cell phone in my purse on days when I'm changing hotels. I also have a week's worth of my prescription meds in the purse. I've never had a problem, but I once saw baggage simply piled up in an open area of the lobby at an upscale US hotel, where anyone could have helped himself to a bag or two.