Kyōsei Tsukui, born Norio Tsukui on March 27, 1961, in Tokyo, Japan, was a Japanese voice actor affiliated with the talent agency 81 Produce. He began his voice acting career in 1983 and continued working until his retirement in 2023. On October 1, 2019, Tsukui publicly disclosed that he had been diagnosed with ALS, which progressively limited his mobility, leading him to use a cane and eventually a wheelchair. On February 17, 2023, he announced his retirement from voice acting due to losing his voice after undergoing a tracheotomy. Following this, he lost the use of his arms and legs and communicated using digital software.

Tsukui contributed to a wide range of anime series, films, and video games over the course of four decades. In the mid-1990s, he voiced Shinji Sekiguchi in the long-running series Chibi Maruko-chan and Makoto Sakaguchi in Azuki-chan. His career included significant roles in adventure and fantasy series, such as Toshio Kazumi in Alice SOS (1998), Straight Cougar in s-CRY-ed (2001), and both Labramon and Shiisamon in the film Digimon Tamers: Battle of Adventurers (2001). He also voiced Johan Tsang in Black Blood Brothers (2006), Pochi in He Is My Master (2005), and Hakka in Zombie-Loan (2007). In the Rozen Maiden franchise, he provided the voice for Laplace's Demon in Rozen Maiden: Träumend. He also appeared in Fantasista Doll as Rinto Mikasa (2013) and Kinnikuman: Second Generation as an unnamed supporting character.

Beyond anime, Tsukui was active in tokusatsu productions, notably voicing Carrigator in Engine Sentai Go-Onger (2008) from episode 7 through 47 and the subsequent film adaptations. His other tokusatsu roles included Deputy Leader Zelmoda in Gekisou Sentai Carranger (1996) and the recurring character Trinoid 12: Yatsudenwani in Bakuryuu Sentai Abaranger (2003). He performed in the video game Psychic Force (1995) as Gates Oltman and Keith Evans, and voiced Pom-Pom in Gunbird 2 (1998). Tsukui was also a singer, having performed the opening theme song S.O.S. for the series Alice SOS. His career is marked by a diverse portfolio of supporting and character roles across multiple genres and formats from the late 1980s through the 2010s.