His father, Oleksandr Danylyuk, is a member of the National Academy of Sciences of Ukraine, while the mother, Lyudmila Danyliuk, taught cybernetics at the Igor Sikorsky Kyiv Polytechnic Institute.

He also studied at the Kyiv Institute of Investment Management (1995) and obtained MBA from the Indiana University Kelley School of Business in 2001.

[2] Oleksandr Danylyuk worked in the private sector as a consultant and investment manager in a number of companies, including TEKT, Alfa Capital and Western NIS Enterprise Fund (WNISEF) in Ukraine.

Oleksandr Danylyuk first joined public service in 2005 as economic advisor to the Ukrainian Prime Minister Yuriy Yekhanurov.

[2] In 2010–2015, Danylyuk chaired the Economic Reforms Coordination Center – an apolitical think tank under the aegis of the Presidential Administration of Ukraine.

[2] The Economic Reforms Coordination Center focused on drafting bills and introducing practices designed to improve investment climate in Ukraine, uphold the rule of law and intensify cooperation with the International Monetary Fund.

He declared his key objectives at the position – better investment climate in Ukraine, transparent rules of doing business for Ukrainian entrepreneurs and foreign investors and public finance reform.

[5][6][7] Danylyuk stated that he had been asked to use government money to fund particular politicians favoured projects, effectively to back political corruption.

[citation needed] Danylyuk initiated dismissal of Roman Nasirov, Head of State Fiscal Service, whom he accused of corruption and sabotaging reforms in tax administration.

[9] Danylyuk used this as formal pretext to remove him from his position in Feb 2017, and later 2018 despite significant push back from the prime-minister succeeded in firing him permanently.

Danylyuk played an instrumental role in this process overcoming resistance of Prosecutor general and other high level officials who attempted to prevent decision of assets freezing.

To prevent it several criminal proceeding were opened against advisors hired by the National Bank of Ukraine, Ministry of Finance and Privatbank.

Oleksandr Danylyuk has repeatedly stressed that reformation of State Fiscal Service is one of the key anti-corruption initiatives, as it will help to improve the business climate in Ukraine.

[12] Later, this escalated into a conflict between, back then, the head of the Finance Ministry and Prime Minister Volodymyr Groysman, when during negotiations with the МВФ, the PM overturned decisions that launched the reform.

Prior to Danylyuk's appointment as the Minister of Finance, he played an active[weasel words] role in implementation of anticorruption reforms in Ukraine.

He was in charge of the development of the Law on National Anticorruption Bureau (NABU) in cooperation with experts and civil society activists, and lobbied its adoption.

Despite strong resistance of the President, Prime-minister and the Parliament the law that de facto removed any powers from Tax Police was passed.

[citation needed] Position to restore the Tax police was promoted by President Poroshenko's ally Nina Yuzhanina.

According to an electronic declaration, in 2019 Danylyuk received a salary of ₴297,395 (US$11,015) as Secretary of the National Security and Defense Council of Ukraine, and ₴1,692,125 (US$62,671) as royalties.

Danylyuk also declared a 2017 Volvo xx60 car and an antique (Sector Watch – gourmet Swiss, silver, the beginning of the 20th century).