Under the planned sale, the Trump International will be renamed the Waldorf Astoria and managed by the Hilton group, according to reports.
The former US president’s company opened the hotel to the public in September 2016.
The Trump Organization, which bought a 60-year lease on the building, had been looking for buyers for the 263-room hotel since 2019.
The deal with Miami-based investment firm CGI Merchant Group is expected to be finalised in the first quarter of next year, sources told The Wall Street Journal and Bloomberg.
The 120-year-old building stands less than a mile away from the White House on Pennsylvania Avenue.
The Trump Organization won approval to redevelop the historic Old Post Office building in 2012.
It opened as a hotel four years later, just weeks after Mr Trump accepted the Republican Party’s nomination to run for president.
During Mr Trump’s term as president, the hotel became popular amongst Republicans visiting the city.
But it also attracted controversy. In 2018, religious leaders called for its liquor licence to be revoked, claiming its owner was “not a person of good character”.
More recently, a congressional investigation found that Mr Trump had “grossly exaggerated” the hotel’s profits when he claimed it made $150m during his term.
The congressional committee said the hotel had instead lost more than $70m while he was in office.
The report also found Mr Trump seemed to have “concealed potential conflicts of interest” related to his ownership of the hotel and his roles as its lender and the guarantor of third-party loans.
Documents showed that the hotel received $3.7m in payments from foreign governments – enough to cover 7,400 nights at the hotel on an average daily rate, according to the committee.
The Trump Organization denied wrongdoing and called the report “misleading”.