White House communications director Anthony Scaramucci is out of the job after less than 10 days in the post.
The former financier, who took the job last Friday, had drawn criticism after calling a reporter to give a profanity-laced tirade against his colleagues.
Mr Trump’s chief of staff Reince Priebus and spokesman Sean Spicer both left their post over his appointment.
The decision was made by Mr Trump’s new chief of staff, John Kelly, US media report. A statement is expected soon.
A three-sentence statement from the White House reads: “Anthony Scaramucci will be leaving his role as White House Communications Director.
“Mr Scaramucci felt it was best to give Chief of Staff John Kelly a clean slate and the ability to build his own team. We wish him all the best.”
Earlier in the day, Mr Trump tweeted about job and wage figures, and insisted there is “No WH chaos”, referring to reports about fighting among White House staff.
Mr Scaramucci had boasted of reporting directly to the president, rather than to his chief of staff.
General John Kelly, who had formerly served as Secretary of Homeland Security, was sworn in on Monday morning at the White House.
The resignation of Reince Priebus came on Friday after Mr Scaramucci posted and then deleted a tweet which many interpreted as an accusation and a threat against Mr Priebus.