Kōki Harasawa, also known by the former stage name Katsuhiro Harasawa, is a Japanese voice actor born on December 4, 1971, in Gunma Prefecture, Japan. He is affiliated with the talent agency Ken Production. His professional career in voice acting began in the late 1990s, and one of his earliest confirmed roles was providing the voice for the character E2 Jet in the anime series Hikarian: Great Railroad Protector.

Harasawa is perhaps best known for his recurring role as Takuya Muramatsu, a student in Class 3-E, across the Assassination Classroom franchise. He voiced this character in the main Assassination Classroom television series, the spin-off series Koro Sensei Quest!, and the theatrical films Gekijōban Ansatsu Kyōshitsu: 365-nichi no Jikan (Assassination Classroom the Movie: 365 Days' Time) and Gekijōban Ansatsu Kyōshitsu Minna no Jikan.

Beyond this prominent role, his anime voice acting credits include a diverse range of supporting characters across numerous series. He voiced Maguro in My Bride is a Mermaid, Yūji Yahagi in Canary, Shinpei Iwata in Space Battleship Yamato 2199, and Hajime Hario in Magikano. Other notable roles include Yohei Yomoda in RahXephon, Yujiro Kamiyama in Hungry Heart: Wild Striker, Hesma in Fantastic Children, and Kōhei Karibuchi in Brave Witches. His filmography also features appearances in well-known series such as The Melancholy of Haruhi Suzumiya, CLANNAD, and Samurai Deeper Kyo.

In the field of video games, Harasawa has contributed his voice to several titles. He is known for voicing Chancellor Cole in The Legend of Zelda: Spirit Tracks, Rot Spinne in Dies irae ~Amantes amentes~, and Bartholomew in Suikoden IV. He has also performed dubbing work for foreign films, including a role in Black Hawk Down.

Harasawa stands at 186 cm tall, making him notably tall among his peers in the industry. He originally worked under the stage name Katsuhiro Harasawa before switching to Kōki Harasawa.