There isn't a definate answer to this, but these are the most approved explainations: cute as a button isn't the original phrase. The word cute is derived from the 1731 english meaning of the word acute, bright or clever. So being as acute as a button makes more sense as it's refering to the shine of polished brass buttons that make them stand out from others... more commonly known as "as bright as a button"; but seeing as this phrase derived from "as acute as a button" (where acute meant clever in 1731) it's easy to see how people mistook it for cute and so the phrase was redirected at cute little things and the meaning of cute was changed over the years... so yes, it came from acute as a button, which mean bright as a button, which has the obvious origins in shiny brass buttons that stood out from the dark coats that the queens men used to wear. Another reasonable explanation, is that the word cute is right, but the word button doesn't refer to a shirt button, but a flower bud, such as the popular name of small flowers called a "bachelor's button". Which obviously makes more sense as baby flowers are much cuter than shirt buttons. That's all I know, but I hope it helped x

CUTE AS A BUTTON - "cute, charming, attractive, almost always with the connotation of being small, 1868 (from the original 1731 English meaning of 'acute' or clever). Cute as a bug's ear, 1930; cute as a bug in a rug, 1942; cute as a button, 1946. Cute and keen were two of the most overused slang words of the late 1920s and 1930s." From "Listening to America" by Stuart Berg Flexner (Simon and Schuster, New York, 1992.) Flexner may have an idea about the word "cute," but he provides no guidance on the question of how a button can be cute. The key to the issue is that it is not the button on a shirt that is meant here, but a flower bud seen in the popular name of small flowers, such as bachelor's button (q.v. "button" (n) in the OED, meanings 2 and 3). The British version is "bright as a button". This makes sense if you think of a polished brass button. The phrase is really only ever used of small people - you'd say that a child, or maybe a small dog, was as bright as a button, but you'd never say it of a six-foot man. So the image is of a small sparky thing. http://www.phrases.org.uk/bulletin_board/41/messages/652.html