Pile foundations represent a highly effective solution for sustaining substantial axial and lateral loads originating from massive superstructures, facilitating the transmission of these loads to the adjacent soil or an underlying hard stratum. The construction of these heavy structures on gentle or steep slopes has increased in the last two decades due to the growing scarcity of level construction sites. The behaviour of pile foundations on flat ground differs from sloping ground due to complex interactions between the piles and soil in different loading conditions. Sloping terrain exerts a notable impact on the stability and bearing capacity of such deep foundation systems embedded in it. This article aims to investigate the performance of pile foundation systems with different configurations and geometries embedded in sloping ground subjected to different types of loading. Soil-pile models were developed using the three-dimensional finite element analysis package PLAXIS 3D. The analyses were performed for the different foundation systems consisting of single and double under-reamed piles, inverted under-reamed piles, and fin piles embedded in homogeneous sloping ground with different sloping angles subjected to lateral, uplift, and compressive loading conditions. The efficacy of pile foundations situated within sloping terrain is evaluated in contrast to those within level ground conditions. The effect of the number and geometry of under-reams for an under-reamed pile foundation system and that of fins, in the case of finned piles, were discussed within the context of sloping ground.