Takehito Koyasu is a Japanese voice actor. Koyasu is part of the voice actor quartet Weiß consisting of Weiß Kreuz voice castmates Shinichiro Miki, Tomokazu Seki, and Hiro Yūki. He used to work for Production Baobab but is now the head of T's Factory, a voice actor company he founded in 1998.

Koyasu is known for his deep, smooth voice, which often lands him in roles that are either villains or lonely bishōnen. Recently, though (as in the cases of Mitsurugi Hanagata from Saber Marionette J, Ryo Kuroyanagi from Yakitate!! Japan, Bobobo-bo Bo-bobo, and Kei Itoshiki from (Zoku) Sayonara, Zetsubou-Sensei) he has been voicing more and more lively/humorous characters. According to Hisaya Nakajo, the manga artist of the series Hana-Kimi, the character of Masao Himejima was designed with Koyasu's voice in mind; the voice actor ended up voicing this character in the series' drama CDs.

On 18 September 2009, he created Velvet Underworld series which is the first drama CD of the series, "The Fool". In the following month, "The Wheel of Fortune" had released as the second drama CD of the series.

子安武人（日语：子安 武人／こやす たけひと Koyasu Takehito，1967年5月5日—），日本男性配音员。出身于日本神奈川县横滨市。身高174cm。A型血。所属事务所为T's Factory。

国中时期原本是想成为电影演员，于是把去学校上课的时间用在看电影看了一整天。直到有一次偶然看了动画《银河铁道999》主角星野铁郎踏上旅途的那一段画面而深受无比感动与幸福。从此对声优产生兴趣，并以“立体性的演技”作为目标。高中毕业之后，进入声优培训学校。

第二代日本声优，连续三年获得最受欢迎男声优。出道作品为《天空戦记 シュラト》，创作了白色猎人。曾与结城比吕、关智一、三木真一郎组成的音乐组合"Weiβ Kreuz"。才华横谥，在创造、画画、作曲、填词、小说等领域都有发展。他的成名作也是由他作为主办人将它TV化和组织四人音乐组合与结城比吕、关智一、三木真一郎合作进行。除了令少女们神魂颠倒之外，子安也有创作其他作品例如年头的和近来TV版。

子安武人，日本男性配音員。出身於日本神奈川縣橫濱市。長男子安光樹也從事配音工作。