The legendary diva is at first indignant when she shows up with her entourage in Barcelona and finds out she has accidentally been booked into a hostel instead of a hotel.
But her anger is turned on its head as she discovers the hostel Casa Gracia’s modern features such as a private room, free wi-fi and cocktail bar.
The film ends with Carey fully embracing the hostel lifestyle by dancing on a table in the bar with other travellers to her hit song Fantasy, complete with gold sequins and doves.
The ad was directed by Nick Ball through Blink and will run online only.
Marek Mossakowski, the global head of brand at Hostelworld, said: "Many people still don’t realise just how much hostels have changed over the past decade. Now they’ve got all the facilities you’d expect from expensive accommodation, but with an affordable price and with a ready-made community of like-minded travellers to share experiences with. Even people with the highest standards can become hostel believers – and divas don’t come any bigger than Mariah Carey!"