Yalkae, a Joker in High School (Korean: 고교얄개; RR: Gogyo-yalgae) is a 1977 South Korean comedy film starring Lee Seung-hyeon, Kim Jeong-hun and Hah Myung-joong, and directed by Seok Rae-myeong.

It was based on Cho Heun-pa's bestselling novel A Legend of Urchins (Yalgaejeon).

[1][2] Na Du-su (Lee Seung-hyeon), nicknamed "Yalkae" (meaning "cheeky, cocky person"), is in his second year of high school and acts like a troublemaker.

[1] When approached by Ho-cheol, Du-su refuses to compensate him.

[1] In 2009, Korea Post issues Yalkae, a Joker in High School as part of the third series of Korean film stamps, which also includes The Road to Sampo, Never Ever Forget Me and Chilsu and Mansu.