Quick Take
- One of Illinois's biggest spiders has a terrifying name, though the reason it earned that name has nothing to do with what you'd expect. Meet the rabid wolf spider →
- The spider with the longest legs on this list is not the one ranked #1, and the size difference will surprise you. See the biggest spider →
- One of these spiders doesn't build a web at all, yet it's among the most effective hunters in the state. Discover its hunting tactics →
- A spider commonly found in Illinois basements shares a famous nickname with a completely different creature, though most people never realize they are not the same thing. Uncover the daddy long legs myth →
While Illinois is famous for Chicago, one of the largest cities in the U.S., the state also has its share of suburban and rural areas, like every other state. Of course, spiders can be found in all of those places. While most of the spiders in this state are so small that they’re often overlooked, some Illinois spiders can get relatively large. Those are the ones that we’re going to focus on today. Let’s take a look at five of the biggest spiders in Illinois and where they hide.
5. Long-Bodied Cellar Spider
| Scientific Name | Size | Danger to Humans |
|---|---|---|
| Pholcus phalangioides | 0.35 inches in body length and up to 3 inches in leg span. | A bite may cause a mild burning sensation. |

Cellar spiders have small, peanut-shaped bodies.
©Vinicius R. Souza/Shutterstock.com
The long-bodied cellar spider is frequently confused with harvestman spiders because they both have the nickname “daddy long legs” or “granddaddy long legs”. This spider has a small, semi-translucent body that can reach up to 0.35 inches in length. It is brown or tan with a darker mark in the center of its carapace. Its long legs can be up to six times the length of its body.
Long-bodied cellar spiders are found in quiet, mostly undisturbed places like attics and basements. They build irregular webs to catch small insects and are harmless to humans. In the rare event of a bite, it would cause nothing more than a mild burning sensation.
4. Black and Yellow Garden Spider
| Scientific Name | Size | Danger to Humans |
|---|---|---|
| Argiope aurantia | 1 inch in body length with a leg span of 2-3 inches. | Rarely bites humans, but it may cause pain and swelling. |

The black and yellow garden spider is a common sight throughout much of the United States
©iStock.com/AwakenedEye
The black and yellow garden spider is also called the writing spider, orb weaver, and many other names. It is known for its silver cephalothorax and black and yellow markings on the abdomen that can sometimes include gray or silver. Its long legs are brownish-red close to its body and banded black and brown toward the ends. It can reach about 1 inch in body length with a leg span of 2-3 inches.
The spider is also identifiable by its large web. The web can measure up to 2 feet in diameter and features an extra-thick section called the stabilimentum, which resembles scribbled handwriting or a zig-zag pattern. This pattern has led to the species being called the writing spider. These spiders live outdoors in tall vegetation near fields and in sunny spots around human settlements. They may investigate disturbances to their webs, but they rarely bite. A bite from this spider is mildly painful and may cause some swelling in the area.
3. American Nursery Web Spider
| Scientific Name | Size | Danger to Humans |
|---|---|---|
| Pisaurina mira | 0.75 inches in body length and a leg span upwards of 3 inches | A bite is mostly harmless to humans, with localized pain and swelling |

American nursery web spiders are primarily found in tall vegetation.
©SDeming/Shutterstock.com
The American nursery web spider is brown or brownish-red. It has a dark stripe running down the center of its cephalothorax and abdomen, bordered by lighter coloring. Its banded legs alternate between brown and light brown. Females can reach up to 0.75 inches in body length with a leg span upwards of 3 inches.
These spiders are known for their maternal instincts. They build a silken nest for their young and then watch over the hatchlings. They are primarily found in tall vegetation, but may also build their webs on bushes, trees, and shrubs near homes. A bite from these spiders is uncommon, but it can cause mild pain and swelling.
2. Rabid Wolf Spider
| Scientific Name | Size | Danger to Humans |
|---|---|---|
| Rabidosa rabida | 0.83 inches in body length with a leg span of 2.5-3 inches | A bite may cause pain, itchiness, and swelling |

The rabid wolf spider is the largest wolf spider native to Illinois.
©Brett Hondow/Shutterstock.com
Rabid wolf spiders are the largest wolf spiders native to Illinois and are among the largest spiders in the state overall. It is easily identified by its light brown color with a dark line down its abdomen and light and dark stripes on its cephalothorax. The front legs of the males are generally dark brown to black. Females are larger than males, with a body that can reach up to 0.83 inches in length and a leg span of 2-3 inches.
This spider can be found in a variety of habitats across the state, including open fields, prairies, and woodlands. The rabid wolf spider does not spin webs; instead, it hunts for prey at night. Although many people consider them dangerous because of their name, size, and speed, they are mostly harmless. A bite may cause localized pain, swelling, and itchiness.
1. Dark Fishing Spider
| Scientific Name | Size | Danger to Humans |
|---|---|---|
| Dolomedes tenebrosus | Up to 1 inch in body length with a leg span of 3-4 inches | A bite may cause a reaction similar to a bee sting |

The dark fishing spider prefers vegetation near a permanent water source.
©iStock.com/JasonOndreicka
Along with the rabid wolf spider, the dark fishing spider is cited as the biggest spider in Illinois. It has a mottled brown and black body, banded black and brown legs, and W-shaped markings on its abdomen. It can grow up to 1 inch in body length with a leg span of 3-4 inches.
These spiders prefer vegetation near a permanent water source, but they can also be found in wooded areas. They are not web-building spiders, but instead hunt for insects and other small invertebrates. Although the size of this spider can be intimidating, it is relatively harmless to people. It will only bite if it feels threatened. If bitten, the sensation is said to be similar to a bee sting.