Devin Nunes, a former California congressmen in Donald Trump's first term, is being replaced temporarily by digital media executive Kevin McGurn as chief executive officer.
The company, Trump Media & Technology Group, didn't give a reason for Nunes leaving or provide a timeline for his permanent replacement.
After soaring shortly before Trump's re-election in November 2024, stock in the company plunged 67 per cent, wiping out more than $US6 billion ($A8.4 billion) in investor wealth.
Trump Media was formed by the Trump family as an alternative to social media giants that had barred him from posting on their platforms after the January 6, 2021 Capitol riots.
It said it would not only take on Facebook and Twitter as a free speech alternative, but eventually could become a media giant competing with streaming services such as Netflix.
The stock soared, but it never gained traction with a wide audience despite the president's frequent use of it for major political announcements, slammed by government ethics experts as a conflict of interest with the presidency.
Since it went public two years ago, Trump Media has lost more than $US1.1 billion ($A1.5 billion). Nunes got total compensation of $US47 million ($A66 million) in 2024, the last year for which figures are available.
The new CEO McGurn said in a statement that the company was "poised to take off".
"In carrying President Trump's unique, singular vision and message, Truth Social stands for the most powerful brand and voice in history of social media and beyond," he said.
The Trump Organisation did not immediately responded to a request for comment.
The company has recently branched into cryptocurrency and another hot business, prediction markets. The latter are online betting venues in which people can wager on sports, entertainment and political events.
The Trump Organisation and the White House have repeatedly denied that there are conflicts of interest between Trump's role as president and the family businesses.