Venture capital (VC) is a form of private equity financing provided by firms or funds to startup, early-stage, and emerging companies, that have been deemed to have high growth potential or that have demonstrated high growth in terms of number of employees, annual revenue, scale of operations, etc. Venture capital firms or funds invest in these early-stage companies in exchange for equity, or an ownership stake. Venture capitalists take on the risk of financing start-ups in the hopes that some of the companies they support will become successful. Because startups face high uncertainty, VC investments have high rates of failure. Start-ups are usually based on an innovative technology or business model and often come from high technology industries such as information technology (IT) or biotechnology.

Pre-seed and seed rounds are the initial stages of funding for a startup company, typically occurring early in its development. During a seed round, entrepreneurs seek investment from angel investors, venture capital firms, or other sources to finance the initial operations and development of their business idea. Seed funding is often used to validate the concept, build a prototype, or conduct market research. This initial capital injection is crucial for startups to kickstart their journey and attract further investment in subsequent funding rounds.

Typical venture capital investments occur after an initial "seed funding" round. The first round of institutional venture capital to fund growth is called the Series A round. Venture capitalists provide this financing in the interest of generating a return through an eventual "exit" event, such as the company selling shares to the public for the first time in an initial public offering (IPO), or disposal of shares happening via a merger, via a sale to another entity such as a financial buyer in the private equity secondary market or via a sale to a trading company such as a competitor.

In addition to angel investing, equity crowdfunding and other seed funding options, venture capital is attractive for new companies with limited operating history that are too small to raise capital in the public markets and have not reached the point where they are able to secure a bank loan or complete a debt offering. In exchange for the high risk that venture capitalists assume by investing in smaller and early-stage companies, venture capitalists usually get significant control over company decisions, in addition to a significant portion of the companies' ownership (and consequently value). Companies who have reached a market valuation of over $1 billion are referred to as unicorns. As of May 2024, there were a reported total of 1248 unicorn companies. Venture capitalists also often provide strategic advice to the company's executives on its business model and marketing strategies.

Before World War II (1939–1945) venture capital was primarily the domain of wealthy individuals and families. J.P. Morgan, the Wallenbergs, the Vanderbilts, the Whitneys, the Rockefellers, and the Warburgs were notable investors in private companies. In 1938, Laurance S. Rockefeller helped finance the creation of both Eastern Air Lines and Douglas Aircraft, and the Rockefeller family had vast holdings in a variety of companies. Eric M. Warburg founded E.M. Warburg & Co. in 1938, which would ultimately become Warburg Pincus, with investments in both leveraged buyouts and venture capital. The Wallenberg family started Investor AB in 1916 in Sweden and were early investors in several Swedish companies such as ABB, Atlas Copco, and Ericsson in the first half of the 20th century.

Only after 1945 did "true" venture capital investment firms begin to emerge, notably with the founding of American Research and Development Corporation (ARDC) and J.H. Whitney & Company in 1946.

Georges Doriot, the "father of venture capitalism", along with Ralph Flanders and Karl Compton (former president of MIT) founded ARDC in 1946 to encourage private-sector investment in businesses run by soldiers returning from World War II. ARDC became the first institutional private-equity investment firm to raise capital from sources other than wealthy families. Unlike most present-day venture capital firms, ARDC was a publicly traded company. ARDC's most successful investment was its 1957 funding of Digital Equipment Corporation (DEC), which would later be valued at more than $355 million after its initial public offering in 1968. This represented a return of over 1200 times its investment and an annualized rate of return of 101% to ARDC.

Former employees of ARDC went on to establish several prominent venture capital firms including Greylock Partners, founded in 1965 by Charlie Waite and Bill Elfers; Morgan, Holland Ventures, the predecessor of Flagship Ventures, founded in 1982 by James Morgan; Fidelity Ventures, now Volition Capital, founded in 1969 by Henry Hoagland; and Charles River Ventures, founded in 1970 by Richard Burnes. ARDC continued investing until 1971, when Doriot retired. In 1972 Doriot merged ARDC with Textron after having invested in over 150 companies.