The 55-year-old entrepreneur, who joined the BBC business series in February 2011 following the departure of James Caan, has chosen to instead sign an exclusive two-year deal with Channel 4.
According to the BBC's Ariel blog, Devey will be fronting a new factual entertainment series called The Intern for the channel, where hopefuls will compete to win an internship with a prestigious British business.
However, she will be appearing in the forthcoming series of Dragons' Den, which is currently being filmed in Salford to air in the autumn.
A spokesperson for the BBC said of Devey's departure: "Hilary has been a formidable Dragon in the Den and we're sorry to see her go.
"She will be breathing fire throughout the new series of Dragons' Den in the autumn on BBC Two but this upcoming series will be her last."
Devey made her approximately £50 million fortune by launching Pall-Ex, a palletised freight network, in 1996.
It was also reported earlier this month that she was raped at the age of 12, after Devey revealed the secret in her new autobiography Bold As Brass.