Midori Katō is a Japanese voice actress, actress, and narrator who has been active in the entertainment industry since 1959. She was born on November 15, 1939, in Tokyo Prefecture, Japan. After graduating from high school, she studied at the Shochiku Music and Dance School, a training school for the Shochiku Opera Company. Her initial ambition was to become a shinpa (new school) stage actress.

Katō began her career by passing a public audition held by NHK in 1959 and subsequently joined the broadcaster's actor training school. She made her acting debut in the NHK television drama "Tenshi no Heya" in 1960. In 1963, after her three-year exclusive contract with NHK ended, a meeting with a producer from Toei Animation led to her first work in voice acting for anime.

Her career in anime began in the mid-1960s, a formative period for television animation in Japan. She quickly became a prominent voice actor for Toei Animation, taking on numerous leading roles. Her early major roles include the titular character Osomatsu (as well as the role of Hatabō) in the 1966 series "Osomatsu-kun", Yoshiko Hanamura in the 1966 magical girl series "Mahōtsukai Sally", and Kan-chan in the 1969 series "Hakushon Daimaō". During this same era, she also voiced characters such as Pontarō Kumoi in "Kaminari Bōya Pikkari-B", Dekoppachi in "Mōretsu Atarō", Chibimaru in "Pyunpyunmaru", and Chuuji Akagi in "Yuyake Banchō". Her voice acting work has been almost entirely with Toei Animation, a collaboration that would define her career.

Katō's most significant and enduring role began in 1969 when she was cast as the voice of the main character, Sazae Fuguta, in the anime adaptation of Machiko Hasegawa's beloved manga "Sazae-san". At the time of the audition, she reportedly believed the series would only last for three months. Instead, it has become a Japanese cultural institution and a national staple. The series was recognized by Guinness World Records in 2013 as the longest-running animated television series. For her continuous work on the show, Katō herself received a Guinness World Record on November 17, 2019, for the longest career as a voice actor for the same character in an animated television series. She is the only original cast member from the show's premiere in 1969 who is still active in the role.

Beyond her extensive voice work for anime, Katō has had a successful career as a television personality. Since 2002, she has been the narrator for the popular home renovation documentary series known internationally as "Makeover! Dramatic Before & After". Her incredulous delivery of the catchphrase "This is how it's done!" became a national sensation in Japan, and she represented the program when the phrase was nominated as one of the top ten entries for the 2003 New Word and Buzzword Awards.

For her contributions to broadcasting, Katō was awarded the 45th Anniversary Special Prize by the Japanese Women's Broadcasting Circle in 2015. In recognition of her iconic status as the voice of "Sazae-san," she was invited to a garden party hosted by the Imperial Family in 2012, where she personally met Emperor Akihito and Empress Michiko.