Aluminum‐based glassy alloys and composites exhibit more than two times higher tensile and compressive strength and superior corrosion resistance compared to the conventional Al alloys. However, the low glass‐forming ability (GFA) of Al‐based glass‐forming compositions restricts the synthesis of large dimension Al‐based amorphous alloys. In contrast, powder metallurgy route leads to synthesis of higher‐dimension Al‐based metallic glasses and composites. A detailed review on the efforts made to improve the dimension and mechanical properties of the Al‐based glassy alloys and composites is essential to further develop these materials for industrial applications. Researchers aspiring to develop high‐strength light‐weight materials can be benefited from such a detailed review on Al‐based amorphous alloys and composites. In this review article, a holistic approach is made to understand the GFA, crystallization behavior, corrosion resistance, and mechanical and electronic properties of Al‐based glassy alloys and composites. The effects of various alloying elements on GFA and criteria to optimize Al‐based glass‐forming alloy composition are discussed. The crystallization behavior is discussed with phase‐separation and quenched‐in nuclei models. The effects of various crystalline phases in the amorphous matrix on corrosion resistance and mechanical and electronic properties are discussed in detail.