He will be responsible for Yahoo's global compliance programmes and legal affairs worldwide.
Bell, who will report directly to Yahoo Chief Executive Officer Marissa Mayer, had joined Yahoo in July 1999.
He has since served in numerous senior roles within the legal department, most recently as interim general counsel, and prior to that as a deputy general counsel for 11 years, the company said in a statement.
"Ron Bell's legal acumen, his outstanding service to the company over the past 13 years, and his leadership within Yahoo's legal team make him an excellent choice for general counsel," Mayer said.
Bell has made his mark on many of the company's most strategic deals and initiatives, including the Microsoft search alliance and the Yahoo Newspaper Consortium, a confederation of media companies representing more than 200 US newspapers, the statement said.
"I am thrilled to be working with Marissa and the entire executive team to help propel Yahoo to its next stage," Bell said.