Taking over from Tim Kirkman, who left Hachette in August after only eight months in the job, Long will be responsible for ad sales across the company's nine magazine titles.
These include women's magazines Elle and Red, the teen title Sugar, and Hachette's TV listings magazines - Inside Soap, All About Soap and TV Hits.
Long, whose start date has yet to be confirmed, will report to the Hachette chairman, Kevin Hand.
While at The National Magazine Company, Long was promoted from associate publisher of Good Housekeeping to publisher in July, following the defection of Chris Hughes to Conde Nast's planned launch Easy Living.
In 2000, he was appointed as the head of media sales for the Diageo subsidiary Translucis, where he was responsible for developing a media sales function for the new company. Before this, he worked as the publisher of Men's Health in 1997 and the associate publisher of GQ in 1990.
Hand said: "Tony brings to Hachette exceptional commercial experience in magazines. He joins us at an exciting time in our strategic development and will help to speed our growth in the market."
Hachette has not launched any magazines this year but Hand announced in August that he was looking to increase its portfolio.