Teddy Geiger, also known as teddy<3, is an American musician, singer-songwriter and record producer. She was originally signed to Columbia Records as an artist, and now focuses on writing and production for other artists. She has written songs for artists including Shawn Mendes, One Direction, Tiesto, Empire of the Sun, James Blunt, Birdy and DJ Snake. Geiger's compositions and productions have sold over 30 million units worldwide and include "Stitches", which won the 2017 BMI Song of the Year award, as well as Mendes' other singles "Treat You Better", "Mercy", "There's Nothing Holdin' Me Back", "In My Blood" and "Lost in Japan".
Geiger began transitioning around the beginning of October 2017, and announced it on Instagram on October 27, 2017, in response to a fan.