Sebastian Siemiatkowski (also spelled Sebastian Siemiątkowski; born 3 October 1981) is a Swedish entrepreneur who is the co-founder and chief executive officer of fintech company Klarna.

Early life

Siemiatkowski's parents moved to Uppsala from Poland in the 1980s. He was born on 3 October 1981 in Sweden but his older sister was born in Poland. Siemiatkowski considers himself as a second generation immigrant. His early influences were Richard Branson and Ingvar Kamprad, founder of IKEA. Siemiatkowski credits the Swedish digital policy of subsidizing the ownership of computers for his success because it allowed his family to acquire their first computer.

Education and career

Siemiatkowski attended high school at Katedralskolan, Uppsala. He holds a master's degree from the Stockholm School of Economics. He started building Klarna at age 23 and co-founded the company with Niklas Adalberth and Victor Jacobsson in 2005. Siemiatkowski had met one of his co-founders when working at Burger King. He owns about 7% of the company, which made him a billionaire, although after Klarna experienced difficulties its lower valuation meant that in 2023 Siemiatkowski no longer counted among billionaires.

Controversy

In May 2019, Siemiatkowski was summoned to the Swedish Ministry of Finance to answer questions regarding perceived issues with Klarnas management of identity theft and the debts of customers. In 2022, as Klarna was experiencing financial difficulty, Siemiatkowski posted a list of employees who were recently dismissed by the company. This unusual course of action was considered as tone deaf by commentators. The Swedish Financial Sector Union expressed regret to have learnt about the job cuts from the media rather than being consulted beforehand.

Personal life

Siemiatkowski married Nina, a marketing executive he first met while attending the Stockholm School of Economics, in 2014. They have three children and live in Stockholm.