In 1998, he obtained a degree from the FSB Academy, majoring in jurisprudence.
He was an advisor to the general directorate of Reform, an international foundation for economic and social reforms. Later, he joined the Basic Element group of companies. He held the position of adviser to the president of the Russian Union of Industrialists and Entrepreneurs (RSPP). At the same time, he was the Deputy Head of the Tax Committee.
In 2008, he joined the Ministry of Economic Development of the Russian Federation. In 2012–2014, as a Deputy Minister, he supervised economic issues in the development of social and cultural industries, the social and labor sphere, social insurance (including health and pensions), demographic policy, social partnership, and the social responsibility of business. Sergey prepared proposals for the forecast on socio-economic development of the Russian Federation.
Since 2014, he has held the positions of Chairman of the Board at NAIDI and Managing Director at InfraONE. NAIDI's primary objective is to promote investment opportunities in Russia's regions, while InfraONE organizes and manages infrastructure projects through PPP and concessionary tools and provides investment consulting and analytical support services for projects.
Since 2016, Sergey Belyakov has been the president of the self-regulating organization Association of Non-State Pension Funds. The organization exists to create favorable conditions for the activities of non-state pension funds in the interests of players in the markets of non-state pension provision and mandatory pension insurance.
Since 2017, he has been a member of the Public Council under the Ministry of Finance of Russia, the Financial Market Council, and the Board of Directors of Expert Rating Agency.
In 2018, he was elected to the Council for the Development of Professional Qualifications, served as a member of RSPP's board, as the Chairman of RSPP's Committee for Trade and Consumer Market, and as a member of the Expert Council of the Financial Ombudsman.
In 2019, Sergey was elected a member of the Supervisory Board of the Financial Literacy Development Association.
In 2018–2021, he was the chairman of the presidium of the Association of Retail Companies. The association was established upon the initiative of representatives of several Russian retail chains to represent the interests of their members and coordinate their activities.
Since 2021, Sergey Belyakov has been the Managing Director of OZON. He supervises the implementation of strategic projects and initiatives related to e-commerce development.