A gas burner is a device that produces a controlled flame by mixing a fuel gas such as acetylene, natural gas, or propane with an oxidizer such as the ambient air or supplied oxygen, and allowing for ignition and combustion.

The flame is generally used for the heat, infrared radiation, or visible light it produces. Some burners, such as gas flares, dispose of unwanted or uncontainable flammable gases. Some burners are operated to produce carbon black.