Polistes humilis, known as the Australian paper wasp, is a species of wasp in the family Vespidae that is found throughout Australia and which has been introduced to northern New Zealand. These paper wasps can be identified by their long thin legs and banded yellow and black coloring. They have been known to re-utilize old nests. While the species does not exhibit morphological class differences, there are distinct behavioral differences between queens and workers. In addition, the species is eusocial and benefits from relatedness between individuals. They are known for delivering a painful sting, especially when their nest is disturbed, a behavior that has been developed as a nest defense mechanism. While wasps are often viewed negatively, they play an important pollination role for many plants.

Polistes humilis is in the genus Polistes, which consists of 150 species that can be found in all regions except the world's coldest climates. Polistes humilis was the only species of the tribe Polistini found in New Zealand after it was accidentally introduced from Australia, prior to the introduction of the Asian paper wasp, Polistes chinensis in 1979. There are 11 different Polistes species found in Australia, and the Polistes humilis is the most prevalent one. Historically, Polistes variabilis has often been misidentified as a sub-species of Polistes humilis. But, recent photogenic analysis has indicated that these are two separate species. The species can be divided into two subspecies, P. humilis humilis which is found in northern Australia and P.humilis synoeus which can be found in the south.

This species of wasp can be identified by its slender body structure and banded coloring. Adults have yellow faces and are 10–15mm long with a tannish-red coloration. Males can be distinguished from females by a yellow marking on the abdomen area. In addition, Polistes humilis are generally bigger than most other paper wasps. Nests of this species can be identified by their cone shaped appearance with multiple hexagonal cells. The species builds its nest out of grey wood fiber material, which is a mixture of its own saliva and wood. Unlike most species of wasps, Polistes humilis colonies have been known to re-utilize old nests from year to year. Some colonies overwinter and shelter above the comb in colder months.

Polistes humilis is mostly found in Australia, particularly in southern Queensland, New South Wales, Victoria, and South Australia. While this species is native to Australia, the species was accidentally introduced to New Zealand in the 1880s and has established a stable population in that country, largely confined to the North Island north of Tauranga and west of Te Kuiti. Environmentally, the highest abundance of P. humilis can be found in shrublands. However, the species can also be found in flax swamps and forest sites.

The colony cycle of Polistes humilis starts in the spring and can begin in three ways. Firstly, the colony cycle can begin with the founding of a new nest, typically by several foundresses. Secondly, the cycle can start with the re-utilization of an old nest, which can be several years old. Thirdly, the cycle can also begin with the continued use of an old nest as this species can overwinter. In situations where old nests are used, new eggs are typically laid around the old cells.

Throughout the year, production of Polistes humilis nests typically follow a distinctive cycle. In the spring, nests are founded by females that have overwintered and have been previously inseminated. After founding, worker females are produced in the late spring and early summer. Males and queen females are produced in the late summer and early autumn.

In Polistes humilis nests, there is an observable hierarchy between reproducing queens and sterile workers. There are no outward physical differences between females; even small females have been known to produce eggs. Since there are no morphological differences between females, behavioral characteristics are the primary determinate of whether a female reproduces or not. These females can be determined by observation as they often receive solid food, honey, and water from worker females returning from foraging. Dominance is often displayed by a "tail wagging" behavior of the lower segment of the species. However, unlike most species that use behavioral characteristics to determine reproductive success, Polistes humilis does not exhibit high competition between females within the nest. This is likely due to the high degree of relatedness among nestmates.

Polistes humilis queens are singly mated, meaning that the eggs of the queen are fertilized by a single male and only one fertilization event occurs per female. However, within each colony, there are an average of two queens. This multiple queen behavior likely developed as a defense mechanism for the nest. Since different males can fertilize each female in the nest, genetic diversity is increased within the nest, which can help defend against disease. In addition, a distinctive characteristic of this species is that there is no inbreeding within P. humilis colonies. This suggests that dispersal is primarily male based and that males do not reproduce in their native colony. Dispersal of males likely happens before mating.