Paige Spiranac wants the haters to butt out of her content ... clapping back at a troll who took issue with her featuring a certain ass-et in a video.

The sports influencer and S.I. Swimsuit model posted a clip of her setting up a new golf bag on Tuesday ... and at one point, she briefly had her back turned to the camera, which put her rump on display.

Some dork was so appalled by the not-so-subtle move ... commenting, "Had to start that second shot with your ass on the camera. Real classy Paige."

Paige -- who has more than four million followers on Instagram alone -- didn't take the criticism sitting down ... and defended herself with a passionate reply.

"I went from having my back connect to my thighs to this," Paige said Wednesday. "It's not the biggest peach now but I've been working harder than I ever have in the gym and also with my diet."

"Heck yeah I'm going to show it off! I'm proud of my body and how hard I've been working to achieve my fitness goals."

Paige also shared a side-by-side shot of her fitness journey to get her point across.

The 32-year-old has had to fend off plenty of wild antics from her followers over the years ... including that one time she had to come out and confirm her boobs have nipples.

Just another day in the life of Paige Spiranac.