The Zigzag Heron (Zebrilus undulatus) is a species of heron in the Ardeidae family, also including egrets and bitterns. It is in the monotypic genus Zebrilus. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela. Its natural habitat is subtropical or tropical swamps.

The Zigzag Heron is a species of the entire Amazon Basin, east of the Andes cordillera, and the five bordering countries on the basin's western periphery, Colombia, Venezuela, Ecuador, Peru, and Bolivia. The range does not extend beyond the Orinoco River basin of Venezuela in the northwest, and in the east-northeast encompasses the Guianas; in the southeast Amazon Basin the range does not extend east of the Tapajós River drainage.