Plae Kao (Thai: แผลเก่า, RTGS: Phlae Kao; literally, 'old wound'), also known as The Scar, is a 1977 Thai romantic drama film directed by Cherd Songsri and starring Sorapong Chatree and Nantana Ngaograjang as two peasants in rural Thailand in a tragic, romantic relationship. The story is based on the novel of the same name by Mai Muengderm. The film's poster was designed by Chuang Moolpinit.

The film was one of the biggest box-office hits in Thailand at the time of its release, earning 13 million baht, a record figure at the time. It was remade in 2002 in Thailand as Kwan-Riam. In 2018, the film was digitized and restored by the Thai Film Archive (public company) and was re-released in Thailand in October 2018.