Oto Ostović was born in 1955 in Feričanci. In 1980 he graduated from the Faculty of Electrical Engineering in Zagreb. He started working in company  RZ „Đuro Đaković“ Slavonski Brod and Secondary school  „August Cesarec“ Našice, but at the beginning of  1989 he moved to company Slavonija IGM d.d. Našice, a member company of  Nexe Grupa.
In 1992 he was employed by cement factory Našice as an electrical engineer in Development and technical department and from 1994 to 1998 he was the head of electroenergetic department. Untill 2000 he worked as a director of  company Slavonija IGM d.d. Našice. From  1 May 2000 till 31 August 2003 he was a director of Production and technical sector in  Našicecement d.d. company. 
From 1 September 2003 he was employed by  Nexe Grupa as a senior advisor for technical operations and since 1 September 2005 till new appointment he had worked as a  director of Cement, lime, concrete and aggregate division and a general manager of   Našicecement d.d. When  Našicecement's Board appointed three members on 1 October 2015 he was appointed president of the Board of Našicecement d.d. and remained at this position till 31 October 2019.  At the same time, since 1 November 2008 till  31 October 2019 he was a member of the Board of Nexe Grupa d.d. Našice.  
On  1 November 2019 he was appointed an advisor to the president of the Board of Nexe Grupa d.d.  He is  a member of Supervisory board in companies Dilj d.o.o. Vinkovci and Polet a.d. Novi Bečej.