The Palaeodictyoptera are an extinct order of medium-sized to very large, primitive Palaeozoic paleopterous insects.

They are known as "six-winged insects" because of the presence of a pair of wings on each of the thoracic segments.

The mouthparts were elongated, and included sharp piercing stylets, and possibly a sucking pump-like organ.

Unlike modern sucking insects, such as the Hemipterans, the mouthparts were held vertically below the head, or projected forwards.

Another distinctive feature was the presence of unusually long cerci, about twice the length of the abdomen.