Is it possible to transfer fat to collar bone? (photos)

yes, you can fat graft to whatever area you want, but I personally think you would be much better off simply doing push ups and making your pectoralis major and deltoid muscles grow. Both these muscles attach to your collarbone and beefing them up would be a much more natural way to fill in that hollowing. 

Hello, thanks for your inquiry, I would say that you have a lovely collar bone, it looks aesthetic and trust me, many women would love to have that looks. Although it is possible to have fat grafted it is not recommendable. Best Wishes ,SincerelyDr. Jaime Campos-LeonBoard Certified Plastic Surgeon 

you can transfer fat wherever you want to. The problem is how it will look. Where do you stop doing it? If your collar bone sticks out and you put fat over it,  it will stick out more and  be larger. It might look less bony, but then people will ask you what the big lump is under your skin. Hard to make this better.