<p>Geocells have recently gained worldwide popularity for being integral to various geotechnical applications. The three-dimensional (3D) cellular network of the geocell mattress provides all-round confinement to the infill soils, providing greater benefits in terms of strength improvement and reduction in deformations. This leads to their widespread applications in various geotechnical structures like embankments, foundations, pavements, slopes, retaining walls, railways, erosion control and slope protection, and waste containment systems. Though geocells were initially used to reinforce subgrades, currently, they provide economical and innovative solutions to many complex geotechnical problems, like shore protection and military defense. This paper presents a state-of-the-art review on various applications of geocells, along with current research trends and prospects. The underlying mechanisms of soil-geocell interactions for each of these applications are explained in detail. The review compiles insights gained from a lot of experimental, analytical, numerical, and field studies on geocell applications and provides future directions based on current research trends.</p>