Fishkeeping is a popular hobby concerned with keeping fish in a home aquarium or garden pond. There is also a fishkeeping industry, as a branch of agriculture.

Fishkeepers are often known as "aquarists", since many of them are not solely interested in keeping fish. The hobby can be broadly divided into three specific disciplines according to the type of water the fish tolerate: freshwater, brackish, and marine (also called saltwater) fishkeeping.

Freshwater fishkeeping is by far the most popular branch of the hobby, with even small pet stores often selling a variety of freshwater fish, such as goldfish, guppies, and angelfish. While most freshwater aquaria are community tanks containing a variety of compatible species, single-species breeding aquaria are also popular. Livebearing fish such as mollies and guppies are among those most easily raised in captivity, but aquarists also regularly breed many types of cichlid, catfish, characin, and killifish.

Many fishkeepers create freshwater aquascapes where the focus is on aquatic plants as well as fish. These aquaria include "Dutch Aquaria", named for European aquarists who designed them. In recent years, one of the most active advocates of the heavily planted aquarium is the Japanese aquarist Takashi Amano.