Ryōta Iwasaki is a Japanese voice actor born on July 1, 1986, in Osaka Prefecture. He is affiliated with the talent management firm Atomic Monkey and is also a member of the theatre company HeroHero Q Company, led by veteran voice actor Tōru Furuya.

Iwasaki's interest in voice acting was sparked during his fifth year of elementary school after listening to a radio program hosted by Megumi Hayashibara. To pursue this career, he funded his own education by saving money and attended Yoyogi Animation School in Osaka, graduating in 2007. He later moved to Tokyo, where he briefly attended the Japan Narration Actor Institute before enrolling in the Atomic Monkey Voice Actor & Acting Institute, graduating as part of its fifth generation. In 2011, he was invited by actress Miki Nagasawa to join the HeroHero Q Company, a theatre troupe headed by Tōru Furuya, whom he admired.

Iwasaki is known for his naturally powerful and loud voice, which he often uses to play energetic and charismatic characters. On radio programs and in public appearances, he frequently speaks in his native Kansai dialect. His distinctive voice once registered 199 decibels on a sound level meter during a variety program segment for the Hypnosis Mic franchise. Beyond voice acting, he has a range of skills and interests, including karaoke, mimicry, and illustration. He is responsible for drawing the original art for his theatre company's enamel pin merchandise.

A significant milestone in Iwasaki's career was being cast as Sasara Nurude in the 2019 multimedia franchise Hypnosis Mic -Division Rap Battle-. This role marked his first challenge performing rap music and has become one of his most prominent and representative characters. Other major anime roles include Inasa Yoarashi in My Hero Academia, Noriyuki Nakamachi in Karakuri Circus, Yusuke Tashiro in Noblesse, Mamango in iii icecrin and its second season, and the younger Sakata twin brother in Eien no 831. He also voiced Hanta Minezaki in Cap Kakumei Bottleman, Kureron-chan in Kaiju Step Wandabada, Jōetsu in ECHIGOBAKUFU, Manu in Okashi na Sabaku no Suna to Manu, Kangaroo-shi in Poccolies, Morita in Snack Basue, Mikoto in NICO/AGONY, and a commentator in Ikari no Okorizaru Kansatsu Nikki. In addition to these series, his filmography includes a wide range of supporting roles in popular series such as Pokémon, Fate/Grand Order, SSSS.DYNAZENON, and Shinkalion.

Iwasaki's work extends into video games and feature films. He voices the character Shūichirō Higashiyama in the Megaton-kyū Musashi game and anime adaptations. He was also cast as Kiminobu Kogure in the critically acclaimed 2022 animated film The First Slam Dunk. In the realm of tokusatsu, he provided the voice for the character Ultraman Xenon in the Netflix series Ultra Galaxy Fight: The Absolute Conspiracy.

He maintains a close working relationship with other voice actors from his agency's seventh generation, forming a group called Atomic7 with Yoshiyuki Miura, Shin Takahashi, and Fumiya Tanaka for online streaming activities.