Buttercream, also referred to as butter icing or butter frosting, is a type of icing used for either filling, coating or decorating cakes. The main ingredients are butter and some type of sugar.

Buttercream is commonly flavored with vanilla. Other common flavors are chocolate, fruits, and other liquid extracts. Food coloring is commonly added if the buttercream is being used as decoration. Buttercream can be piped or spread in decorative patterns and shapes.

American buttercream or mock cream is a simple buttercream made by creaming together butter and powdered sugar to the desired consistency and lightness. Some or all of the butter can be replaced with margarine, or shortening.^{[failed verification]} A small amount of milk or cream is added to adjust the texture. Usually twice as much sugar as butter by weight is used. Some recipes also call for powdered milk or meringue powder.

Compared to other types of buttercream, American buttercream has fewer ingredients, and is quicker and easier to make. It is also sweeter because of the high amount of sugar. Because it does not have an egg or cooked base, it is less stable and melts more easily in warm temperatures.

Meringue buttercream is made by beating softened butter with either Italian or Swiss meringue until the mixture is emulsified and light. The meringue must be cooled to room temperature in order not to melt the butter (which has a variable melting point below 35 °C (95 °F)) as it is subsequently beaten in.

The meringue gives buttercream a structure that is more stable in warm temperatures.

Swiss meringue is made by heating granulated sugar and egg whites until the sugar dissolves, then whipping it until it forms a meringue. The meringue is then whipped with butter and flavorings.

Italian meringue is made by drizzling a hot sugar syrup into already whipped egg whites while continuing to whip. The meringue is then whipped with butter and flavorings.