Yasuo Iwata was born on January 19, 1942 in Iwate, Japan. As an anime voice actor, Iwata began his career when he provided voices for anime in the mid 1990s, with his first production being a Lupin III special in 1994. He would go on to provide several voices for anime television and films during the mid-to-late 1990s and the early 2000s.

Iwata's anime roles include: Nanbutsu Isasaka in the Sazae-san television series (he was the third voice actor for this character), King and Mago-Consigliere in the Cosmic Baton Girl Comet-san television series, Toshiaki Ooyama in the Darker Than BLACK television series, Dietman in the Ghost in the Shell: Stand Alone Complex 2nd GIG television series, Old Man in the Heat Guy J television series, Principal Ikeno in the anime film JAPAN, Our Homeland, Marius in the Last Exile television series, The President in the Lupin III: The Columbus File special, a role in the Lupin III: Dragon of Doom special, a role in the anime film NITABOH, the Shamisen Master, Shiina's grandfather in the Shadow Star Narutaru television series, Asona in The Vision of Escaflowne television series, Kukai in the Zenki television series, Jonathon Mann in the Eat-Man '98 television series, and Dr. Ijuuin in the Tokyo Mew Mew television series.

Yasuo Iwata's most well-known role was for providing the voice for Nanbutsu Isasaka, a romance novelist character, in Sazae-san. The series itself started on Japanese television back in 1969, and is an all-ages comedy and slice of life anime. There were two voice actors who provided the voice for Nanbutsu Isasaka prior to Yasuo Iwata: Sanji Hase (who provided the voice for Nanbutsu Isasaka from 1969-1978) and Eken Mine (who provided the voice for Nanbutsu Isasaka from 1985-2002). Iwata became the third voice actor for Nanbutsu Isasaka after Eken Mine left the role in 2002.

Iwata provided the voice for a doctor in the Japanese version of the Kileak the Blood 2: Reason in Madness video game for the PlayStation. He also made an appearance on the 1997 drama CD, The City of Lost Children; this was released in Japan in 1997 by Nippon Crown. And in 1983, Iwata also made an appearance on L. Subramaniam's album, Comfortable.

Sadly, Yasuo Iwata passed away on October 24, 2009 from lung cancer. He was 67 years old, and was still providing the voice for Sazae-san's Nanbutsu Isasaka, at the time of his death.