Sujono Hadinoto was born on 28 June 1915, in Blora, Central Java, in what was then the Dutch East Indies (now Indonesia).

He began his education at a Hollandsch-Inlandsche School and a Hogere Burgerschool, before advancing to the Rechts Hogeschool in Batavia, graduating in 1942.

[1][2][3] During the Dutch colonial period, he worked as a superintendent at a company owned by the Mangkunegaran, before opening a law practice.

[8] In conversations with American diplomats, Sujono indicated that he was against the nationalization of foreign petroleum companies operating in Indonesia.

[9] In 1950, he also joined the Indonesian delegation led by Lambertus Nicodemus Palar to Moscow to establish relations with the Soviet Union.