the BBC reports that E L James, the creator, is the top-earning author of 2012.
The success of the Fifty Shades trilogy has propelled EL James to the top of Forbes' list of the highest-earning authors.
The British writer earned $95m (£61.5m) last year, the business magazine said.
She knocked crime author James Patterson off the top spot after three years. He took second place with $91m.
James's first novel Fifty Shades Of Grey sold 70 million copies in eight months. At its peak, the entire trilogy earned her more than $1m a week.
The Fifty Shades novels have been a publishing phenomenon, and have had particularly strong sales in the e-book market.
The series began as a piece of fan fiction, inspired by Stephanie Meyers' Twilight series, but was re-written before publication as a novel.
Meyers, who took 13th place on the Forbes list in 2012, did not make the top 15 this year.
James's success is almost unprecedented, said Forbes, as most of the names on its annual list are established authors whose earnings derive from sales of their extensive back catalogues.
James Patterson, meanwhile, will release his 115th book later this year.