Francia Raisa is getting ripped again ... but this time we're talkin' muscles.

Selena Gomez's best friend is back in the gym getting her sweat on just months after donating her kidney to save Selena's life. You can see her scars where doctors made the incision, but we suggest you check out her it's-always-bikini-season bod.

The surgery took its toll on Francia, a fitness queen forced to put her workouts on hold.

She wasn't ready to pose for paps last week on the set of her new TV show, "Grown-Ish," but she's now ready to show us what she's got.

And we dig it.