5'6" 120lbs ordered a size small. Fits perfect. Cute dress and very comfortable! My only complaint is it's quite thin fabric and somewhat see-thru. Notice the picture from the side, you can see the tag thru the dress. I am wearing a nude colored bra and nude spanx and I can see where the spanx stop on my leg. It does accentuate any tummy fat because it's so form fitting.