Slated to take over her position is Dan Pfeiffer, her deputy, sources familiar with the move told The Washington Post.
Dunn, a Democratic media consultant, took over the job on an interim basis earlier this year when Ellen Moran left to take a job within the Commerce Department, the Post said.
Dunn was expected to remain as a consultant to the White House on communications and strategy.
Pfeiffer began working for Obama in 2007, first as the traveling press secretary during Obama's presidential run, then overseeing the campaign's communications operation.
Celebrity Families of 2014 [PHOTOS]