Chasing the Dragon (Chinese: 追龍; Sidney Lau: Jui¹ Lung⁴), previously known as King of Drug Dealers, is a Hong Kong-Chinese action crime drama film directed by Wong Jing and Jason Kwan. The film stars Donnie Yen as Crippled Ho, based on real life gangster Ng Sik-ho and Andy Lau reprising his role as Lee Rock from the film series of the same name.^[1] The film is about an illegal immigrant from China who sneaks into British-colonized Hong Kong in 1963 and transforms himself into a ruthless and emerging drug lord. ^[2][3] The film is a remake of the 1991 film To Be Number One.^[4]

Chasing the Dragon II: Wild Wild Bunch, a sequel-in-name-only featuring new characters and a new storyline, was released in June 2019.

Director Wong Jing personally flew to Canada in 2016 to persuade Yen to star in his film Chasing the Dragon, while Yen was filming XXX: Return of Xander Cage at that time. Yen was convinced by Wong's sincerity, playing a non-traditional role of a villain with limited fighting scenes and the opportunity to work alongside Andy Lau.^{[citation needed]} Yen flew back to Asia to take part in the film after filming Return of Xander Cage in 2016.

In September 2017, Chasing the Dragon was released to mixed reviews from critics.^[5] It was a huge hit with audiences in most Mandarin-speaking parts of Asia (including China and Singapore), beating Hollywood blockbuster Blade Runner 2049 and Jackie Chan's The Foreigner, despite being marketed less heavily. In Hong Kong, Chasing the Dragon earned more than 10 times the box office gross of The Foreigner. In China, it earned US$86 million.^[6]

Chasing the Dragon was released as a digital, Blu-ray and DVD combo pack on January 23, 2018.^[7]