Fish balls are balls made from fish paste which are then boiled or deep-fried. Similar in composition to fishcake, fish balls are often made from fish mince or surimi, salt, and a culinary binder such as tapioca flour, cornstarch, or potato starch.

Fish balls are popular in East and Southeast Asia, Europe (especially Northern Europe), and some coastal countries of West Africa. In Asia they are eaten as a snack or added to soups or hotpot dishes. They are usually attributed to Chinese cuisine and the fish ball industry is largely operated by people of Chinese descent. European versions tend to be less processed, sometimes using milk or potatoes for binding. Nordic countries like Norway, Denmark and Sweden each have their own variation.

There are two variants of fish balls, differing in textures, production method, and primary regions of production.

While the ingredients and methods are similar between countries, differences can be noted in terms of elasticity, colour, and flavour. Fish balls in Hong Kong and the Philippines can be more firm, darker, and have more fishy taste and aroma than their Malay and Singaporean counterparts. Taiwanese fish balls have more bounce and more air incorporated to allow for soaking up soups or sauces.

Typically fish are shredded, coarsely ground, or pounded, then undergo prolonged mixing with added salt and crushed ice until a smooth texture is attained. Other ingredients are added, such as sugar, monosodium glutamate, transglutaminase, or starches, and then water is added to ensure the ball has a "soft, springy texture." This technique, similar to the process of making surimi, uncoils and stretches previously wound and tangled protein strands in the fish, which produces food with a firm "bouncy" texture. In Taiwan, the term "Q" is used to describe this ideal bouncy texture.

In commercial production, the balls are shaped by an extruding machine, and set in water between 30 and 45 C. before boiling, cooling, then packaging. The setting time is an important part of manufacture because in addition to giving the balls a translucent appearance, the shape will be maintained after packaging. They can be sold uncooked (after setting), boiled, or fried (after being boiled).

The variety of fish used in surimi can affect commercial fish ball production, due to the difference in thermal stability between tropical fish and cold-water fish. Economically, fish ball production adds value to lower-priced fish.

Scandinavian fish balls are made of completely pureed fish, milk, and potato flour (or potato starch), and they are shaped without additional processing, which produces a softer texture. This type of fish ball usually comes in metal cans or transparent plastic containers containing stock or brine and also requires a setting period prior to canning.