Shigeki Nakanishi is a Japanese entertainer and voice actor, recognized primarily for his role in the long-running anime series Ahare! Meisaku-kun. He is one half of the comedic duo Nasunakanishi, performing alongside his partner Akiyuki Nasu. This background in comedy informs his performance style, particularly in his most notable voice role.

Nakanishi’s primary and most substantial voice acting credit is the character Sweets in the anime Ahare! Meisaku-kun. The series, which aired from 2016 to 2022, is a collection of comedy shorts following the students of Ryuuguu Elementary School as they interact with parodies of famous literary and folk tale characters. Nakanishi voiced the role of Sweats across multiple seasons, including the show's third, fourth, fifth, and sixth seasons. The character is described as a loud-mouthed, energetic, and dim-witted class president who comes from a wealthy family and is known for his obnoxious passion and distinctive laugh. For several seasons, Nakanishi also contributed to the series' music, performing on the ending theme songs as part of the cast group Ryuuguu Shou 7-nen C-gumi and Ryuuguu Shou 8-nen C-gumi.

Beyond his voice work, Nakanishi's career is deeply intertwined with his comedy partner. Together as Nasunakanishi, the duo has worked extensively on the Ahare! Meisaku-kun franchise, with Nasu voicing the protagonist, Meisaku Matsuda. Nakanishi has also performed theme songs for the show alongside his comedy partner. This collaboration represents the most significant recurring partnership in his professional work as a voice actor. His other known voice role includes a part in the television series Kayoe! Chuugaku. His career achievements are centered on the success and longevity of his role in Ahare! Meisaku-kun, a show that produced over 230 episodes across six seasons.