Rapid urbanisation in earthquake-prone regions has intensified the demand for effective lateral force resisting systems capable of protecting structural integrity under strong ground motion excitation. Fluid viscous dampers (FVDs) have emerged as a leading passive energy dissipation technology, distinguished by their velocity-proportional force output, inherent phase-angle offset between peak damping force and peak structural displacement, wide operational frequency bandwidth, and consistent thermal stability under repeated seismic loading cycles. This paper presents a critical, structured review synthesising two decades of analytical, numerical, and experimental FVD research, systematically addressing constitutive modelling frameworks — spanning the linear dashpot and the more physically rigorous Maxwell model incorporating series spring stiffness — damper classification into linear (velocity exponent α = 1) and nonlinear (α < 1) variants, optimal placement strategies including inter-storey drift-guided and topology-based allocation, comparative performance against concentrically braced frames (CBFs), moment-resisting frames (MRFs), and buckling-restrained braces (BRBs), and compliance with the supplemental damping provisions of ASCE 7-16, IS 1893:2016, and the loss-estimation methodology of FEMA P-58. Synthesised findings from studies on reinforced concrete and steel moment frames spanning 5 to 35 storeys demonstrate peak displacement reductions of 20–96%, inter-storey drift reductions of 27–97%, and variable base shear modulation governed by supplemental damping ratio, velocity exponent, and input ground motion frequency content. FVDs consistently outperformed displacement-dependent devices in limiting residual drift and floor acceleration demands — critical determinants of post-earthquake functional recovery. Nonetheless, research gaps persist in experimental characterisation of bi-directional and torsionally coupled loading responses, quantitative treatment of soil–structure interaction effects on damper force demand, and the development of a generalised, code-agnostic optimisation framework for FVD sizing across diverse building typologies and seismic hazard regimes.