A Better Tomorrow III: Love & Death in Saigon (Chinese: 英雄本色3-夕陽之歌) is a 1989 Hong Kong action drama film directed, co-written, and co-produced by Tsui Hark, the producer behind the first two films in the series. It is a loosely based prequel to John Woo's A Better Tomorrow and A Better Tomorrow II.

John Woo wrote a screenplay for a third installment, but he never got to direct it due to having had artistic differences with Tsui during the filming of the second film. Instead, the original screenplay later became Bullet in the Head. The two films have many parallels, most notably, both being set in the Vietnam War.

The film stars Chow Yun-fat, who reprises his role of Mark Gor from the first film, Tony Leung Ka-fai and Anita Mui. Set during the Vietnam War, it sets up the story of how Mark became the character he was in the original film. The second part of the title Love & Death in Saigon (夕陽之歌 or Song of the Setting Sun in Chinese) is also the title song for this movie. It was sung by Mui, who was also the leading lady in this third installment.