Variations in the geometry and physical properties of the Earth’s lithosphere and its sub-lithosphere, such as density and thickness, lead to formation of tectonic structures and cause changes in gravity and topography signals. They are, therefore widely used for examining the structure of the Earth’s crust and its upper mantle. Low-orbit gravity satellites have measured gravity signals with wavelengths greater than about 200km. Long-wavelength components of the gravity field mainly arise from deep Earth sources, including the core, lower mantle, or their boundaries, whereas medium- wavelengths and short-wavelengths are associated with shallower layers such as the lithosphere and the upper mantle. Therefore, to investigate near-surface structures, the long wavelengths effects must be removed from gravity and topography signals. In this study, by analyzing gravity, geoid and topography data the influence of geotectonic structures on the three-dimensional geometry and rheological behavior of the lithosphere in the northwestern Indian Ocean is examined. This research involves the analysis of seafloor topography and geoid and gravity signals to investigate the development of complex features such as mid-ocean ridges, transform faults, and multiple island chains on the NW of Indian Oceanic Plate. The relationships between geoid-to-topography and gravity-to-topography ratios and geological processes are evaluated using theoretical models. Two key processes are considered: the mechanical response of the lithosphere to loading and the convective flow in the upper mantle. Then, their effects on three-dimensional geometry of the oceanic lithosphere are analyzed. The results enhance our understanding of geodynamic factors and processes influencing large-scale deformation in this region and provide deeper insight into indirect geophysical observations such as geoid and topography.