Charles Hoskinson (born 5 November 1987 on Maui, Hawaii) is an American entrepreneur who is a co-founder of the blockchain engineering company IOHK, and the Cardano blockchain platform, and was a co-founder of the Ethereum blockchain platform.

Hoskinson attended Metropolitan State University of Denver and the University of Colorado Boulder to study mathematics.

In 2013, Hoskinson quit a consulting job to begin a project called the Bitcoin Education Project. According to Hoskinson, the limited supply makes Bitcoin like a digital form of gold.

He joined the Ethereum team as one of five original founders with Vitalik Buterin in late 2013 and held the position of chief executive. Buterin and the Ethereum team removed Hoskinson in 2014 after a dispute over whether the project should be commercial (Hoskinson's view) or a nonprofit (Buterin's view).

In late 2014, Hoskinson and former Ethereum colleague Jeremy Wood formed IOHK (Input Output Hong Kong), an engineering and research company, to build cryptocurrencies and blockchains. IOHK's key project is Cardano, a public blockchain and smart contract platform that hosts the ADA cryptocurrency. Hoskinson did not pursue venture capital for Cardano, saying that it ran counter to the blockchain's principles. Hoskinson has also said that venture capital involvement might lead to an outsized control of a project.

In September 2021, Hoskinson donated $20 million to Carnegie Mellon University's philosophy department to establish and run the Hoskinson Center for Formal Mathematics with the goal of studying formal logical systems.

Hoskinson contributed $1.5 million to fund a 2023 Galileo Project expedition led by astronomer and "alien hunter" Avi Loeb to explore debris from the meteorite CNEOS 2014-01-08 (also called IM1) that crashed into the Pacific Ocean in 2014. Loeb argued that this object could have been created by alien life, an idea that lacked widespread support from the scientific community. The expedition reported finding tiny metallic spheres from the object on the ocean floor.

Loeb claimed his team's analysis of these spherules did not match any known alloy, though it was unclear whether they were artificial or natural in origin. However, a paper published by the American Astronomical Society In October showed that the chemical compositions provided by Loeb's analysis most closely matched human-produced coal ash.

As of 2022, Hoskinson purchased an 11,000-acre buffalo ranch near Wheatland, Wyoming, donated equipment to the Platte County Sheriff's Office, and purchased a restaurant in Wheatland. He also has a farm in Boulder, Colorado.

In 2023 Hoskinson, along with his father and brother, who are both physicians, opened the Hoskinson Health and Wellness Clinic in Gillette, Wyoming. The clinic focuses on anti-ageing and regenerative medicine. The director of the clinic said it had cost $18 million. Hoskinson said cryptocurrency would be accepted in the future.

Hoskinson was criticised after his private jet was ranked among the top 15 biggest polluters in the US on the Climate Jets website. Commentators contrasted the "green" reputation of Cardano with Hoskinson's personal travel. He defended his jet use, saying the plane had been used for charters for the band Metallica and film industry workers.