Will chin filler make my face look less round? (photo)

Absolutely Magical4313!
You could benefit from a combination of dermal fillers and masseter reduction with Botox.  Neuromodulators such as Botox are great for slimming the face by relaxing and shrinking the masseter muscles. 
Fillers to the cheeks and chin are used to add contour and lengthen the face.  The combination of the two treatments can give you a more angular facial shape for a more mature look.
Take a look at our video and our blog link explaining the benefits of dermal fillers and facial slimming with Botox.
We hope this is helpful.  Good luck and stay beautiful!
~ Mabrie Facial Institute

Hi,
 Good question and thanks for sharing your picture. It would be important to see your profile view (from the side) to better assess your chin projection and overall facial shape and proportions. Sometimes botox is used to the masseter muscle to help “slim” a face that is square in shape. Chin, prejowl, and jawline filler can be used to help contour the jawline but would be best assessed in person. 
 Best,
Dr. Gerecci