The former US president, who is banned from Twitter, Facebook and YouTube, hopes to launch his Truth Social app next year.
He claims it will provide a forum that will not restrict freedom of speech.
And he argued the financial backing “sends an important message to Big Tech that censorship and political discrimination must end”.
A statement on the company’s website reads that the app “encourages an open, free, and honest global conversation without discriminating against political ideology.”
Digital World Acquisition Corp raised $293 million (£250m) for the venture in September, but it is unclear who the rest of the investors are.
The firm is expected to merge with the former president’s Trump Media and Technology Group.
Revealing the venture in October, Trump said: “We live in a world where the Taliban has a huge presence on Twitter yet your favourite American president has been silenced.
“This is unacceptable.”
Speculation is rife that Trump will return to run in the 2024 presidential election campaign.
He has released polling figures which suggest he would beat President Biden in swing states Arizona, Georgia, Michigan, Pennsylvania and Wisconsin.
Trump last week responded to claims that he became “bored” in a meeting with Prince Charles back in 2019.
The former US President spoke about his run-in with the Prince of Wales in a new interview with ex-UKIP politician Nigel Farage – which aired on GB News on Wednesday night (December 1).
In the same interview, Trump told Farage that he has never been a “fan” of Meghan Markle, and that the Sussexes’ actions have “hurt” Her Majesty.
