Provided is an integrated fan-out package including a die, an insulating encapsulation, a redistribution circuit structure, a conductive terminal, and a barrier layer. The die is encapsulated by the insulating encapsulation. The redistribution circuit structure includes a redistribution conductive layer. The redistribution conductive layer is disposed in the insulating encapsulation and extending from a first surface of the insulating encapsulation to a second surface of the insulating encapsulation. The conductive terminal is disposed over the second surface of the insulating encapsulation. The barrier layer is sandwiched between the redistribution conductive layer and the conductive terminal. A material of the barrier layer is different from a material of the redistribution conductive layer and a material of the conductive terminal. A method of fabricating the integrated fan-out package is also provided.