Seung Jun Kim, also known as Kim Seung-jun, is a prominent South Korean voice actor born on October 17, 1967, in Seoul, South Korea. He began his career in 1990 after joining the Korean Broadcasting System's voice acting division, where he worked exclusively for four years before becoming a freelancer. Kim studied broadcasting and entertainment at the Seoul Institute of the Arts. He rose to stardom in the late 1990s with his voice roles in two iconic series: as Zelgadis Greywords in Slayers and as Kaede Rukawa in the Korean dub of Slam Dunk.

Kim has an extensive filmography in anime, providing the Korean voices for numerous leading characters. He is the long-standing voice of Roronoa Zoro for the Korean dub of One Piece, a role that extends to several of the franchise's movies, including One Piece Film: Strong World, One Piece Film: Z, and One Piece: Nejimaki Shima no Bōken. He also voices Sesshomaru in the InuYasha series and its films, including InuYasha the Movie 3: Swords of an Honorable Ruler and InuYasha: The Final Act, and Vegeta in Dragon Ball Z Kai and Dragon Ball Super.

His other major anime roles include Seiran Shi in The Story of Saiunkoku and its second series, Asuma Shinohara in Patlabor: The Movie, Subaru Sumeragi in Tokyo Babylon and Tokyo Babylon 2, Haji in Blood+, Takumi Mayama in Honey and Clover, Yuki Sohma in Fruits Basket, Count D in Pet Shop of Horrors, Train Heartnet in Black Cat, Griffith in the Berserk: The Golden Age Arc film trilogy, Wolfram von Bielefeld in Kyo kara Maoh!, Jack Atlas in Yu-Gi-Oh! 5D's, Kouichi Sakakibara in Another, Ryuho in s-CRY-ed, Aru Akise in The Future Diary, Illumi Zoldyck in Hunter × Hunter, Yūto Kiba in High School DxD, Keiki in The Twelve Kingdoms, Ryu Amakusa in Tantei Gakuen Q, and Shinohara Asuma in Patlabor. His work also includes the role of Noboru Terao in Voices of a Distant Star, Hazama Itsuro in 8 Man After, Kai in Bucky - The Incredible Kid, Kaenon (Nozomu Kanou/Kanon) in Nurse Angel Ririka SOS, and Babel I in Babel II.

Beyond animation, Kim is recognized for dubbing the Korean voices of many international film stars, including Brad Pitt, Johnny Depp, Matt Damon, and Christian Bale. He is also well known for voicing SpongeBob SquarePants in the Korean dub of the long-running series, as well as Woody from the Toy Story films. A recurring aspect of his career is his involvement in the Korean dubs of numerous popular long-running anime series, frequently collaborating with Korean broadcasting networks such as KBS, SBS, Tooniverse, and Animax. Kim is highly regarded by fans, who often refer to him by the nickname Wang-ja-nim, meaning The Prince, a testament to his distinguished, tender voice and the noble or charismatic characters he frequently portrays.