麦田圈（英语：Crop circle）是在麦田或其他农田上，透过某种力量把农作物压平而产生出的几何图案，主要出现于欧洲与北美洲，英国的Stonehenge（巨石阵），English hill figures（英国hill图：多为马的图形），West Kennet Long Barrow（West Kennet长冢）等古迹附近的农作物田园中。

最早出现的麦田圈文献记载是在1678年8月22日，出现在英国东部赫特福郡的一份木板版画小册子刊物里面，名为「魔鬼的收割者」。但是一位深入研究调查该插画的学者Andy Thomas，在2005年所发表的一篇文章里面，发现这幅插画共有四种不同的版本，而且每种版本里面所绘画的魔鬼眼睛及身体的斑纹都不一样。该文章作者的结论里面，告诫大众极有可能这个插画的来源是个恶作剧。

A crop circle or crop formation is a pattern created by flattening a crop, usually a cereal. The term was first coined in the early nineteen-eighties by Colin Andrews. Crop circles have been described as all falling "within the range of the sort of thing done in hoaxes" by Taner Edis, professor of physics at Truman State University. Although obscure natural causes or alien origins of crop circles are suggested by fringe theorists, there is no scientific evidence for such explanations, and human causes are consistent for all crop circles. A commentary in The Guardian noted that "[i]t is still open to dispute whether some are caused by natural phenomena or all created by human hand."