Barcelona Airport Arrivals

By 'arrival side' do you mean "airside"/"inside security", or "landside"/"before security"?

Airside after we land in Barcelona is it possible to just wait around for a few hours to exit the airport ?

For a few hours airside I'd find a lounge. I have Priority Pass, but even if I had to pay for a day pass, it would be worth it to me.

Sorry I should’ve explained my situation fully. Basically we arrive in BCN late night at 00:00 but the hotel check in isn’t until later in the day. Which is why we want to wait a few hours to leave the airport till at least we can go to the hotel to drop off our luggage which won’t be till 9 am. So for a situation like that there should be some seating areas in the arrival area right if we were to wait few hours before exiting the airport?

Ouch! Spending the night in the airport is something I would never plan to do. Is it even open overnight? Some arent.

Arriving at midnight isn't that late. I'd book my hotel for check-in a day earlier, and advise then you won't be there until nearly 1am.

Yes I agree but Unfortunately we already made this stupid mistake of booking the flight at the time and hotel was also booked already 😕😕😕

Find another hotel for when you arrive and get some rest.

Yes I’ll look for one!

There is a Sleep and Fly at the BCN airport after arrivals.
Within the sleep and fly there are lounges ; I used the one included in my Priority Pass membership. Max stay was 4 hours though I think it is unlikely the lounge areas are open 24 hours.

You could check their nightly room rental rate though and see if you can just get a bed/room for the night you could stay in for your early AM hours. I imagine they allow after hours check in if you have a room reserved.

Or of course book another hotel for this arrival night that allows for after hours check in.
Some hotels are now using an app for bluetooth key access with your phone so you don't ever need to go to the front desk if you use that and upload your passports in advance. Hilton I think does that for one but modern smaller non chains may as well.

Thank you this is all helpful! I’ll look into it!