[2] Grill grew up in rural Hampshire[3] and worked on a farm as a young adult, experiences which have influenced his art and writing.
[2] He graduated from University College Falmouth, is dyslexic, and runs a weekly art club at a local school.
[4][5] Two of Grill's books are Junior Library Guild selections: The Wolves of Currumpaw (2016)[6] and Earth Verse (2018).
[11] When Grill won the Kate Greenaway Medal in 2015 at age 24 for Shackleton's Journey, he was the youngest person to have earned the award since 1960.
[12] In addition to the Greenaway Medal, Grill won the Colin Mears Award.