Iwata Tatsuaki (岩田 達明, 1926 - 2022) was a Nihon Ki-in professional Go player who reached 9-dan in 1964, the first of Kitani's pupils to do so.
Iwata was once known as Iwata Masao (正男). He completed 800 professional wins in 2004.
Innovator of the Iwata Formation.
GoBase page: http://gobase.org/information/players/?pp=Iwata%20Tatsuaki