In this paper, an attempt is made to understand the dynamics of a fractional order three species Leslie-Gower predator prey food chain model with simplified Holling type IV functional response by considering fractional derivative in Caputo Sense. First, we prove different mathematical results like existence, uniqueness, non-negativity and boundedness of the solutions of fractional order dynamical system. The dissipativeness of the solution of the FDE system is discussed. Further, we investigate the Local stability criteria of all feasible equilibrium points. Global stability of the interior equilibrium point have also been discussed here. Using realistic parameter values, numerically it has been observed that the fractional order system shows more complex dynamics, like chaos as fractional order becomes larger. Analytical results are illustrated with several examples in numerical section.