IN AT O: Lucy Kaylin is succeeding Susan Casey as the editor in chief of O, the Oprah Magazine, Hearst Magazines president David Carey said Monday afternoon. Casey had been the editor of the highly regarded Sports Illustrated Women, which Time Inc. shut down in 2002, and came to remake O in 2009. Until recently, she had been a visible promoter of the magazine. Three weeks ago, she and Self’s Lucy Danziger cohosted a party for volleyball player Gabrielle Reece’s new book.

Now she is “returning to Hawaii to work on her new book,” according to Hearst. O, one of the most successful magazine launches in recent memory back when it appeared in 2000, struggled last year, ending nearly 10 percent down in newsstand sales from the year before although total circulation rose 1 percent, according to the Alliance for Audited Media. In advertising the magazine also suffered — down 15 percent year to year, according to Media Industry Newsletter. “I am grateful to Susan Casey, whose creativity, energy and talent has taken the magazine to another level, and I am looking forward to O’s ‘next chapter’ with Lucy Kaylin at the helm,” said Oprah Winfrey, the magazine’s founder and editorial director.

This story first appeared in the April 30, 2013 issue of WWD. Subscribe Today.

Kaylin had been the deputy editor since 2009 and takes over formally in early May.