Melania Trump cashed in big on her documentary ... even though moviegoers mostly stayed home.

The First Lady's Amazon-backed documentary "Melania" turned into a massive payday for her ... with President Trump's newly released annual financial disclosure revealing Melania personally pocketed $10.71 million from the project.

That's an eye-popping haul considering the film reportedly brought in only about $16 million at the worldwide box office -- meaning FLOTUS' payday alone topped half of the movie's total ticket sales.

The filing also shows she earned roughly $521,000 from her memoir ... along with more than $6 million from NFTs and other collectibles.

As TMZ previously reported, the documentary made headlines every step of the way ... from vandalized posters and its star-studded Kennedy Center premiere to brutal reviews and a mixed audience response to Amazon's reported $75 million investment.

The controversy eventually spilled into Washington, where members of Congress demanded answers from Amazon over whether the project was a legitimate business deal ... or an effort to curry favor with the Trump administration.

POTUS insisted the doc was Melania's deal, not his ... saying, "That was done with my wife," while Amazon founder Jeff Bezos has repeatedly denied any "pay-to-play" arrangement.

Now, thanks to the latest financial disclosure, there's finally a price tag on Melania's side of the deal ... $10,710,000. It's nice work, if you can get it.