Ottó Toldi graduated as an ecologist in 1988 from Lajos Kossuth University in Debrecen. For 20 years, he worked as a biotechnologist at the Agricultural Biotechnology Research Center in Gödöllő, progressing through every level of the hierarchy from doctoral student to deputy director-general. His work took him to many countries around the world. He spent a year and a half in Finland and nearly three years in England at the University of Sussex in Brighton, as a Royal Society Fellow. During this period, he co-authored thirty-six English-language scientific articles, two internationally published technical books, six invited book chapters, and thirty-one conference abstracts.

In 2010, Ottó Toldi made a sharp career change to public administration. As a biotechnologist, he had always been interested in the utilization of biomass as a renewable industrial raw material and energy source. Initially, he continued this work from a different perspective within the National Development Ministry. Subsequently, as deputy head of department, he led a small but enthusiastic professional team that developed the National Energy Strategy, adopted by Parliament in 2011, along with its action plans. He continued to be involved in the development of almost all relevant strategic materials (new National Energy Strategy, National Energy and Climate Plan, National Clean Development Strategy) in various capacities.

His work was recognized by the Hungarian Academy of Sciences with the Bolyai Prize in 2002 and a ministerial award in 2013. He joined the Climate Policy Institute on March 1, 2021, as a research leader, hoping to be a valuable member of this young and ambitious team and to help shape its scientific profile. Since mid-2023, Ottó Toldi has been serving as a senior researcher at the Institute