Ran Masaki (Japanese: 真咲 乱, Hepburn: Masaki Ran) (July 26, 1965 - ) is a former Japanese AV idol, pink film actress and gravure model who was active in the 1980s and rose to prominence as Nikkatsu's final "SM Queen" (SMの女王, SM no joō) from 1985 to 1986. Masaki starred in three Roman Porno films (two of them written by Oniroku Dan).^[1] She also appeared until 1987 in several adult videos mainly focusing on her full-figured body.

Some sources, such as the JMDB,^[2] erroneously list her as the same person with Ran Mizukami (水上 乱, Mizukami Ran), a pink film actress of the same period, also known as the fetish model Sawako (佐和子).^[3]