Toni Braxton Shows Off Nearly-Nude Body To Celebrate 56th Birthday

Singer Toni Braxton is looking STUNNING at 56, and she's gotta know it ... which is why she shared a racy snap of herself to celebrate her birthday.

The R&B star posted the nearly-nude shot on Saturday, as she turned 56 -- captioning the hot shot, "In my birthday suit..."

Folks in the comments sounded off with their "Happy Birthday" wishes ... and took the time to point out how great she looks. As one person put it, "Best BDAY photo EVER!!"

Toni's been through the wringer lately -- as we reported, she underwent a procedure last year after doctors found an 80% blockage in her main coronary artery ... which could've resulted in a fatal heart attack.

She also suffers from lupus and lost her sister, Traci, to cancer last year ... something she actually attributed to a slip in checkups with the doctor.

We got Toni in NYC earlier this year, filling us in on how grateful she was months after going under the knife -- and telling us why Traci's passing made her just think she was sad, not sick.