Cosmopolitan, or simply Cosmo, is a magazine published monthly from New York by the Hearst Corporation. It was founded in 1886 as a "magazine for the whole family".

Through the years Cosmopolitan, magazine has been able to open versions in various languages, such as Spanish, Swedish and French.

Cosmopolitan, which in format became basically a women's magazine when Helen Gurley Brown became chief editor in 1965, reaches readers in many countries worldwide.

In earlier incarnations, such as under John Brisben Walker from 1889 to 1905, it was one of America's leading markets for fiction, and for a briefer period was known for important investigative journalism. Circulation had been in decline for years before Brown took over and remodelled the magazine.

It was banned in Singapore until recently.