Gallagher was staying at the five-star W Hotel in LA while working on his debut solo album, High Flying Birds, when he found out that King George Tupou V had booked into a room on the same floor.
A source told UK newspaper The Sun: 'Noel was baffled by men in suits with ear pieces keeping an eye on things along his corridor.
'It was only later in the trip that he realised what was going on, when room service was taking so long to arrive.”
The source added: 'It turned out it was being checked out before arriving at his door. He was laughing with the lads in the studio about it being like a scene from Coming To America in the room next door.'