Insect collecting refers to the collection of insects and other arthropods for scientific study or as a hobby. Most insects are small and the majority cannot be identified without the examination of minute morphological characters, so entomologists often make and maintain insect collections. Very large collections are preserved in natural history museums or universities where they are maintained and studied by specialists. Many college courses require students to form small collections. There are also amateur entomologists and collectors who keep collections.

Historically, insect collecting has been widespread and was in the Victorian age a very popular educational hobby. Insect collecting has left traces in European cultural history, literature and songs, e.g., Georges Brassens's La chasse aux papillons (The Hunt for Butterflies). The practice is particularly common among Japanese youths.^{[citation needed]}

Insects may be passively caught using traps such as funnels, pitfall traps, bottle traps, malaise traps, or flight interception traps, some of which are baited with small bits of sweet foods (such as honey). Entomologists collecting nocturnal insects (especially moths) during faunistic survey studies might utilize ultraviolet light traps such as the Robinson trap. Aspirators, sometimes called "pooters", suck up insects too small or delicate to handle with fingers.

Active capture of insects often involves using nets. Aerial insect nets are used to collect flying insects. The bag of a butterfly net is generally constructed from a lightweight mesh to minimize damage to delicate butterfly wings. Sweep nets are more rugged, and used to collect insects from grass and brush. A sweep net is swept back and forth through vegetation quickly turning the opening from side to side and following a shallow figure eight pattern. The collector walks forward while sweeping, and the net is moved through plants and grasses with force. Sweeping continues for some distance and then the net is flipped over, with the bag hanging over the rim, trapping the insects until they can be removed. Other types of nets used for collecting insects include beating nets and aquatic nets. Leaf litter sieves are used by coleopterists and to collect larvae.

Once collected, insects must be killed before they damage themselves trying to escape. Killing jars are used on hard-bodied insects. Soft-bodied insects, such as those in the larval stage, are generally fixed in a vial containing an ethanol and water solution.

There are several different preservation methods that are used; some of which include: dried preservation (pinning), liquid preservation, or slide mounts. Another (now mostly historical) approach is caterpillar inflation, where the innards were removed and the skin dried. Pinning is by far the most common form of insect preservation.

It is better to pin an insect that has died recently enough that it has not dried yet, because it allows the thoracic muscles to adhere to the pin. Previously dried specimens must have glue applied to the pin location to avoid spinning. The large majority of the time insects are pinned vertically through their mesothorax and slightly off-center to the right of the mid-line. The pin should sit with 1/4 of the pin above the insect as to allow enough room for labels to be readable underneath.

When pinning insects with wings, it is important to display them properly: Lepidoptera wings should always be spread. When drying insects with wings such as butterflies, setting paper is used to position the wings.