And if you look solely at "unicorn" startups that are worth $1 billion (£803 million) or more, they're even starting to rival Silicon Valley.
We ranked the 34 coolest startup CEOs in Europe, taking into account the founders' personal careers, as well as how innovative their companies are.
We've decided to use a broad definition of "startup" for this list, in line with VC Paul Graham's definition as pretty much any fast-growing company. So we've got companies that range in size from a handful of people all the way up to companies that are on the verge of going public.
We also decided not to include Israeli startups on this list. You can see our ranking of tech startups in Israel here.
Additional reporting by Shona Ghosh, Hannah Roberts, and Lara O'Reilly.