The announcement was made by the president-elect's transition team early Thursday.
Conway served as Trump's third campaign manager and is widely credited with helping guide him to victory.
She is also a frequent guest on television news programs.
Conway had said previously that she planned to move her family to Washington to serve Trump, either inside or outside the administration.
The transition team says Conway "will work with senior leadership" in the White House "to effectively message and execute the administration's legislative priorities and actions."