Forgotten is a 2017 South Korean mystery thriller film written and directed by Jang Hang-jun. The film stars Kang Ha-neul and Kim Mu-yeol, with Moon Sung-keun and Na Young-hee in supporting roles.

Kang Ha-neul (Korean: 강하늘; February 21, 1990), born Kim Ha-neul (김하늘), is a South Korean actor. He is best known for his roles in television dramas The Heirs (2013), Misaeng: Incomplete Life (2014), Moon Lovers: Scarlet Heart Ryeo (2016), When the Camellia Blooms (2019) and Insider (2022). Known as a prolific Chungmu-ro actor, he has also starred in the movies Twenty (2015), Dongju: The Portrait of a Poet (2016), New Trial (2017), Midnight Runners (2017), Forgotten (2017), The Pirates: The Last Royal Treasure (2022), and Love Reset (2023).