Riccardo Onorato, also known professionally as Niseem Onorato, is an Italian actor and voice actor. He was born in Rome on October 24, 1966. He is the son of actor and voice actor Glauco Onorato and the brother of voice actress Sara Onorato. Originally named Riccardo, he adopted the name Niseem in the year 2000 following a period of travel in India.

In the field of anime dubbing, Onorato is recognized for his Italian voice work on several prominent Japanese animated series and films. He is known for providing the voice of the protagonist Joe Yabuki, also known as Rocky Joe, in the series Tomorrow's Joe 2, which is the second season of Ashita no Joe. He also portrayed the character Griffith in the film trilogy Berserk: The Golden Age Arc. His other notable anime roles include Sesshomaru in the series Inuyasha and its films, Captain Yamato in Naruto Shippuden, Paptimus Scirocco in Mobile Suit Zeta Gundam, Orfeo della Lira in the OAV series Saint Seiya: The Hades Chapter - Inferno, Nicolas Vacheron in Gunbuster 2: Diebuster, General Logi in Blue Dragon, and Kumadori in One Piece. He also voiced Gourry Gabriev in a new dubbing of The Slayers.

Onorato has built an extensive and prolific career in dubbing that extends well beyond animation. He is widely known as the primary Italian voice actor for numerous international film stars, including Jude Law, Benedict Cumberbatch, Eric Bana, Josh Duhamel, and Mark Wahlberg. His work dubbing Benedict Cumberbatch in the film The Imitation Game earned him the Leggio d'oro award for Voice Actor of the Year in 2015. Onorato is also active as a stage actor and has appeared in several Italian television productions, such as the fiction series Cuori rubati.