Black, 66, has most recently been chairwoman of Hearst Magazines, publisher of Cosmopolitan, Good Housekeeping and other titles.
The school system, the nation's largest, has 1,500 schools and more than one million students.
Black is replacing Joel Klein, the one-time U.S. Justice Department trust buster, who is now joining News Corp., which owns The Wall Street Journal, Fox News and other media properties. In his new role as executive vice president, Klein will advise NWS on investing in educational market digital initiatives, according to this WSJ story.
Under Klein, other leading lights also were drawn to help the school system, including Caroline Kennedy, the daughter of John F. Kennedy and Jacqueline Kennedy.
Earlier: Black, Vega get 2010 Al Neuharth Award for Excellence in the Media