"Mercy" is a song by Canadian singer and songwriter Shawn Mendes. It was co-written by Mendes with Ilsey Juber, Danny Parker and Teddy Geiger, with the latter handling the song's production with Jake Gosling. It was released on August 18, 2016, through Island Records as the third promotional single, and later as the second single on October 18, 2016, from his second studio album, Illuminate (2016).
"Mercy" is written in the key of B minor with a common time tempo of 144 to 152 beats per minute. Mendes's vocals span from B3 to A5 in the song.
On September 21, 2016, a music video directed by Jay Martin was released. It features Mendes singing, switching between him drowning in a locked car in the ocean and him performing the song with instruments.