Leanchoilia is a four-eyed arachnomorph arthropod known from Cambrian deposits of the Burgess Shale in Canada and the Chengjiang biota of China. It was about 5 centimetres (2.0 in) long and had long, whip-like feelers mounted on frontal arm-like appendages. Its internal organs are occasionally preserved within the substrate in three dimensions. It had stalked compound eyes as well as pit-like ocelli.