Small beer (also, small ale) is a beer/ale that contains very little alcohol. Sometimes unfiltered and porridge-like, it was a favored drink in Medieval Europe and colonial North America. It was sometimes had with breakfast, as attested in Benjamin Franklin's autobiography. Before public sanitation, water-transmitted diseases, such as cholera, were a significant cause of death. Because alcohol is toxic to most water-borne pathogens, and because the process of brewing any beer from malt involves boiling the water, which also kills them, drinking small beer instead of water was one way to escape infection.

The Zulu and other Southern African peoples brew a small beer from sorghum. The drink, known as utshwala, is brewed by women and, due to its high nutritional value, is considered a staple food in the area. It also serves a social purpose as its sharing is part of community life.

Small beer/small ale can also refer to a beer made of the "second runnings" from a very strong beer (e.g., scotch ale) mash. These beers can be as strong as a mild ale, depending on the strength of the original mash. This was done as an economy measure in household brewing in England up to the 18th century and is still done by some homebrewers. Small beer was also produced in households for consumption by children and servants.

Metaphorically, small beer means a trifle, a thing of little importance. The term is also used derisively for commercially-produced beers which are thought to taste too weak.

Small ale in literature

Besides Franklin's autobiography, small ale turns up in both the writings of William Shakespeare and in Ellis Peters' Brother Cadfael series. A famous poem mentions small beer:

Here lies a Hampshire Grenadier

Who caught his death Drinking small cold beer.

A good soldier is ne'er forgot

Whether he dieth by musket Or by pot.