The 16-year-old, who has represented England at U-17 level, has been with Chelsea for some time but never actually signed a professional contract with the club.
The Blues were keen to have him commit his future by offering him a professional deal, but he has decided to look elsewhere for his next move.
Goal reports that Juventus are close to announcing him as a new signing after Bayern, PSG, and Schalke were all previously interested.
Iling-Junior confirmed himself on Instagram that he was indeed leaving Chelsea.
“Full of vast emotions, being at Chelsea from such a young age has truly built me, not only as a the player I am today but also as a person,” the social media post read.
“It’s been a blessed journey and I’m deeply thankful for all those in the Academy. From the groundsmen, kitchen staff, players, coaches, the list goes on.
“I’m filled with gratitude at the time and effort put into my development, leading me to where I am today.
“I would also like to give thanks to the people around me, my family and friends who have consistently supported me.
"Finally, I’d like to thank God for blessing me with this opportunity and protecting me throughout. This is just the start.
"I wish Chelsea all the best for the seasons ahead."
The departure of a promising youngster will come as a blow to Chelsea, but at first-team level they are expected to continue spending after already laying out £136m on Hakim ZIyech, Timo Werner, Ben Chilwell, and Malang Sarr.
Kai Havertz and Jan Oblak remain on their target list.