"Treat You Better" is a song recorded by Canadian singer and songwriter Shawn Mendes. It was co-written by Mendes with Teddy Geiger, and Scott Harris. It was released on June 3, 2016 through Island Records as the lead single from his second studio album, Illuminate (2016). The music video was released on July 12, 2016 and features a storyline about an abusive relationship.

Who wrote treat you better by shawn mendes? Okie... think carefully first, then make a decision:
To answer this question, we should know that: It was co-written by Mendes with Teddy Geiger, and Scott Harris. So, the answer is Mendes with Teddy Geiger , and Scott Harris.