Mariah Carey's Las Vegas outfit is definitely a hole-in-one ... 'cause she wore a skintight outfit to tee off at Top Golf!
The singer-songwriter shared a series of snaps highlighting her clothes to Instagram ... leaning on a golf club and ready to whack one a couple hundred yards.
MC shared a couple other pics too ... and, she's looking glamorous in each one with her mesh bodysuit -- which gives fans a glimpse of her bra -- and high heels.