The lists in this article are a list of devices categorized as types of telescopes or their associated systems. They are divided into numerous groups, due to the different possibilities of classifying them according to their use (professional, amateur and commercial subtypes); of its optical design; and its mechanical or constructive design. Telescopes can also be classified based on where they are placed, such as space observatories. An important determining factor is the type of light or particle being observed, including devices called "telescopes" that do not form an image or use optics. Some telescopes are classified by the task they perform; for example solar telescopes (designed to observe the Sun), Dobson-type telescopes (designed to reduce their cost and be portable), or aerial telescopes (designed to maximize their focal length, reducing aberration problems).

Optical telescopes can be classified by their three basic optical designs (refractor, reflector, or catadioptric), by subsets of these types, by the way they are constructed, or by the task they perform. They all have their different advantages and disadvantages, and are used in different areas of professional astronomy and amateur astronomy.

Optical and other types of telescopes are attached to different types of mounts: