Warland, 16, had progressed through Glory's NPL Academy after joining the club's Development Centre in 2011 and 'is set to spend the next three years at Craven Cottage', a Glory media release read.
"The move to Fulham represents a fantastic opportunity for Riley," Glory football director Jacob Burns said, "and while it is sad to see a young prospect depart, he goes with our very best wishes.
"He has been with the club since the age of nine and his progress is a testament to the hard work of every coach he has worked under within our two-star academy here at Glory, as well as to his own hard work and dedication.
"Riley joins a lengthy list of players who have followed the clear pathway that exists within our academy structure and gone on to earn opportunities at top overseas clubs."