大食蚁兽（学名：Myrmecophaga tridactyla）是食蚁兽的一种，分布在美洲部份地区，生活在草地、落叶林和雨林地区。主要以蚂蚁和白蚁为食，一天最多可食30,000只昆虫。

大食蚁兽在现存四种食蚁兽中体型最大，体长可达1.8-2.4米。体重通常为29-65公斤。体毛长而坚硬，可长40厘米，尾部密生长毛，头细长，眼耳极小并吻成管状，无齿，舌细长并能伸缩，借以舐食蚁类、白蚁及其他昆虫。前肢除第五指外，均具钩爪，后肢短，五爪大小相仿。体灰白色，背面两侧有宽阔的黑色纵纹，纹的边缘白色。

包括两个亚种：

The giant anteater (Myrmecophaga tridactyla), also known as the ant bear, is a large insectivorous mammal native to Central and South America. It is one of four living species of anteaters and is classified with sloths in the order Pilosa. This species is mostly terrestrial, in contrast to other living anteaters and sloths, which are arboreal or semiarboreal. The giant anteater is the largest of its family, 182–217 cm (5.97–7.12 ft) in length, with weights of 33–41 kg (73–90 lb) for males and 27–39 kg (60–86 lb) for females. It is recognizable by its elongated snout, bushy tail, long fore claws, and distinctively colored pelage.