Microfoam is finely textured milk used for making espresso-based coffee drinks, particularly those with latte art. It is typically made with the steam wand of an espresso machine, which pumps steam into a pitcher of milk.

The opposite of microfoam is Macrofoam (also called dry foam, in contrast to the wet foam of microfoam), which has visibly large bubbles, a style of milk, traditionally used for cappuccinos.

Microfoam is shiny, slightly thickened, and should have microscopic, uniform bubbles. It is not as viscous or "foamy" as macrofoam – it is better described as "gooey" and resembles melted marshmallows or wet paint. There have been a variety of names used for this ideal standard, such as "microfoam", "velvet milk", "microbubbles", and so forth.

The decorative application of microfoam is called latte art, which involves making patterns in espresso-based drinks. Microfoam is essential for this as the microscopic bubbles give definition and stability to the patterns, which are harder to achieve with macrofoam which disperses more readily. Latte art is traditionally associated with lattes, as the name suggests, but can also be used in cappuccinos and other drinks.

A cappuccino made with microfoam is sometimes called a "wet" cappuccino. However, cappuccinos typically use thicker macrofoam, with a layer of dry foam floating on the top of the drink. Latte macchiato is another drink which generally has separate layers of dry foam and liquid milk, but microfoam is occasionally used instead. Microfoam may also be added to brewed coffee in a café au lait, and faint latte art can be produced. Microfoam may also be used in a steamer (a "coffee-free" cappuccino), though this can instead be made with dry foam.

As it requires a skilled barista to produce microfoam (especially when used for latte art), it is a sign of attention to quality, and a defining characteristic of the third wave of coffee.

Microfoam is usually created with the steam wand of an espresso machine. This is the quickest method and provides precise control over the timing and depth of air injection. Alternative methods are rarely as effective for producing microfoam, but some are acceptable for macrofoam. These include whisking, shaking, and hand pumps. Dedicated electric milk frothers may also be used, usually consisting of a motorized whisk.

When using a steam wand, the volume and type of foam is controlled by the barista during the steaming process, and loosely follows these steps: