Sebastian Siemiatkowski
Sebastian Siemiatkowski | |
|---|---|
| Born | October 3, 1981 Sweden |
| Occupation(s) | Business leader, entrepreneur |
| Known for | Co-founder and CEO of Klarna |
Sebastian Siemiatkowski (also spelled Sebastian Siemiątkowski; born 3 October 1981) is a Swedish business leader and the co-founder and CEO of the fintech firm Klarna. By 2022, his wealth was valued at approximately $3.2 billion following Klarna's increased market valuation; however, as of 2025, he no longer holds billionaire status.
Early life
Born in Sweden to Polish immigrant parents who settled in Uppsala during the 1980s, Siemiatkowski is a second-generation immigrant. His elder sister was born in Poland. Inspired by entrepreneurs such as Richard Branson and IKEA’s founder Ingvar Kamprad, he acknowledges that Sweden’s digital initiatives, which supported computer ownership, enabled his family to purchase their first computer—a pivotal element in his achievements.
Education and career
Siemiatkowski completed his secondary education at Katedralskolan, Uppsala and earned a master’s degree from the Stockholm School of Economics.
At 23 years old, he began developing Klarna, co-founding the company in 2005 alongside Niklas Adalberth and Victor Jacobsson; he met one of his co-founders while employed at Burger King.
Klarna’s valuation reached $31 billion in 2021, elevating Siemiatkowski to billionaire status. The following year, the company encountered financial difficulties and reduced its workforce by 10%. Controversy arose when Siemiatkowski publicly disclosed the names and email addresses of the employees who were laid off, attracting criticism for lack of sensitivity. The Financial Sector Union of Sweden expressed disappointment over learning about the layoffs through media channels instead of formal discussions and subsequently initiated legal action against Klarna.
In December 2024, Siemiatkowski announced that Klarna would halt employee growth, emphasizing that artificial intelligence has the potential to replace human roles depending on its implementation.
Personal life
In 2014, Siemiatkowski married Nina, a marketing professional who founded a digital platform linking donors with community nonprofits. She played an important role in selecting the marketing agency responsible for Klarna’s branding. The couple lives in Stockholm with their three children.