However, less than 24 hours before Mr Miller quit, AJ Delgado, another senior Trump staffer, put out a series of since-deleted tweets suggesting the communications director was involved in a sex scandal.
"Congratulations to the baby-daddy on being named WH Comms Director!" Delgado wrote.
"When you try to put on a brave face and tweet about nonsense to distract, your feed looks like @Jason MillerinDC's,' she tweeted, before adding, "When people need to resign graciously and refuse to, it's a bit ... spooky."
Miller and Delgado found themselves in trouble earlier this year when it was revealed they had visited a Las Vegas strip club together the day before the final presidential debate.
Miller was one of the main spokesmen for Trump's transition team.
He has now handed all of his responsibilities to incoming White House press secretary Sean Spicer, who will serve as communications director as well as press secretary.
