Celine Dion's saying Donald Trump using her songs will not go on ... putting out a statement saying she didn't authorize Trump to use "My Heart Will Go On," -- and questioning his song selection.

The singer-songwriter's management company put out a statement just minutes ago ... saying they found out DJT and his running mate J.D. Vance played a clip of Celine singing the "Titanic" theme at their Montana rally.

They're making it clear ... Celine didn't give them permission to play it, and she's not endorsing political candidates to use her song.

The statement ends with a question to the candidate ... with the group questioning why Trump would use this specific song.

It's a pretty strange choice to be fair ... and, the addition of the video seems to make even less sense -- but, Trump's known for making some pretty eclectic choices with his pre-speech playlist.

People on social media noted he played a track from "The Lion King" as well as other more conventional picks ... but, he only had Celine on video as far as we know.

While Trump's tossing in a celeb cameo -- albeit, a nonconsensual one -- in his rally ... Kamala Harris and Tim Walz are staying away from Hollywood.

We broke the story, the Harris/Walz campaign's keeping its distance from celebs for the DNC ... trying to avoid claims the event's a "liberal Hollywood event." That doesn't mean no celebrity cameos -- just less, according to our sources.

So the Dems are avoiding celebs ... and, Donald Trump better avoid Celine -- 'cause it sounds like she's not messing around.

We've reached out to Celine's team for more clarification of her statement ... so far, no word back.