Jang Jeongjin was a prominent South Korean voice actor known for his prolific career in dubbing and narration. He was born on September 10, 1953, and passed away on October 11, 2004. He joined the voice acting division of Tongyang Broadcasting Company (TBC) in 1977, which later merged with the Korean Broadcasting System (KBS) in 1980, making him part of the 15th KBS cohort.

His voice work is most recognized in dubbing foreign films and series. He notably provided the Korean voices for numerous characters in the dubbed broadcasts of the Super Sentai series, which were adapted into the Power Rangers franchise in Korea. His extensive filmography in this genre includes roles in dubbed versions of Earth Task Force Goggle-V, Space Commando Bioman, Earth Protector Flashman, Warriors of the Light: Maskman, and Liveman: Warriors of Peace. Beyond animation and tokusatsu, his voice became widely familiar to the public through his narration for television programs and commercials. He was particularly known for his narration on comedy shows and his work for the program SBS Inkigayo.

Throughout his career, Jang Jeongjin held several leadership positions within the voice acting community. He served as a director of the Korea Voice Actor Association from 1998 to 1999 and later as the 24th president of the KBS Voice Actor Association from 2000 to 2001. He also shared his expertise as an adjunct professor in the Department of Entertainment and Acting at Gongju Visual Information University starting in 2003.