The Sunday Times Rich List 2023 put the Dyson family fortune at about £25bn, making it the fifth richest in the UK. Forbes gave James Dyson's own net worth as $15.1bn in September 2026. The two figures measure different things and different years.
The wealth comes from Dyson, which the family owns entirely. Its 2025 revenue was £6.13bn, with operating income of about £600m. The company is private and has never taken venture capital.
It began with cyclonic separation, which removed the bag from the vacuum cleaner. Dyson built about 5,127 prototypes from 1978 to 1983, and his wife Deirdre's salary as an art teacher helped pay for them. He sold the G-Force in Japan in 1986 and founded Dyson in 1991.
Not every bet paid off. In 2017 he committed £2bn of his own money to an electric car and cancelled it in October 2019. In January 2019 he moved the company's headquarters to Singapore.