The 25-year-old Harry Potter star released his first single earlier this week. The track is named Lightning, and appears on the soundtrack of his new movie Postman Pat.
The film is an animated feature based on the British television series of the same name. Stephen Mangan voices the title character, while Grint brings Pat's rival Josh to life. Postman Pat premieres May 23 in the U.K.
Celebrity Families of 2014 [PHOTOS]