The two said on Thursday they were quitting in protest over the storming of the US Capitol building the day before.
Ms Chao — the wife of Senate Republican Leader Mitch McConnell — said in an email to staff that the mob attack “has deeply troubled me in a way that I simply cannot set aside”.
She said her resignation will take effect on Monday.
In a letter to Mr. Trump, Ms. DeVos said the attack on the Capitol was unconscionable.
“There is no mistaking the impact your rhetoric had on the situation, and it is the inflection point for me,” she wrote, adding her resignation would be effective on Friday.
With twelve days left of Mr. Trump’s beleaguered Presidency, many aides were already heading for the exit, making some of their resignations mere symbolic gestures.
But the sudden departures suggested revulsion among some over the president’s encouragement of supporters who inflicted chaos and mayhem on the Capitol on Wednesday, in an ultimately futile effort to stop formal validation of Joe Biden’s election win.
Among the latest departures were deputy national security adviser Matt Pottinger, a leading aide on Mr. Trump’s China policy, who left abruptly on Wednesday, and Tyler Goodspeed, acting chair of the White House Council of Economic Advisers.
They were followed on Thursday by at least five senior directors at the White House National Security Council (NSC) responsible for advising Mr. Trump on Russia, the Middle East, Africa, defence policy and weapons of mass destruction.