Monster (Japanese: 怪物, romanized: Kaibutsu) is a 2023 Japanese psychological dramatic mystery thriller film directed, co-produced, and edited by Hirokazu Kore-eda from a screenplay written by Yuji Sakamoto. It stars Sakura Andō as a mother who confronts a teacher after noticing disturbing changes in her son's behavior. The film marks the first time Kore-eda has directed a film he did not write himself since Maborosi (1995). This was the last scoring project by Ryuichi Sakamoto (no relation to Yuji Sakamoto), who died two months before its release; the film is dedicated to his memory.

Monster had its world premiere at the 76th Cannes Film Festival on 17 May 2023, where it competed for the Palme d'Or and was honored with the Queer Palm as well as the Best Screenplay award. The film was released in Japan on 2 June 2023. It received widespread critical acclaim with special praise for its screenplay, direction, acting, editing and musical score and appeared in many lists of top ten years best.