The United States adaptation of the Dragons' Den format is called Shark Tank.
Shark Tank began in the United States in 2009 and uses the same broad premise: entrepreneurs present companies or products to wealthy investors and seek funding in exchange for equity. The American investors are called sharks rather than dragons.
The series is part of a wider international television format that began with Japan's Money Tigers. Different countries have adapted the idea with local investors, branding, and broadcasting arrangements while preserving the pitch-and-negotiation structure.
Shark Tank is therefore not the original programme and is not simply another name for the British series. Dragons' Den is the British version, while Shark Tank is the American version. The shows share a format but have different panels and national business contexts.