This thesis investigates the optimum allocation and capacity of the Distribution Generators (DGs) and Distribution Static Synchronous Compensator (DSTATCOM) in the radial distribution grid to attain the best reduction in the active power dissipations, voltage drop, and annual loss cost. Four various optimization algorithms are proposed in this research namely Differential Evolution (DE), Genetics Algorithms (GA), Multi-Objective Differential Evolution (MODE), and Multi-Objective Genetic Algorithm (MOGA). First, the multi-objective function is changed into a solitary one by multiplying each objective function with a weight factor. Then, GA and DE are used to attain the optimum capacity and place of the DG and DSTATCOM in the radial distribution grid. For the case of the MOGA and MODE, the multi-objective functions are directly used without applying the weighted vector approach. After the Pareto Front are obtained, the weighted vector approach is applied to select one solution. Finally, to check the performance of the methods, IEEE 33 bus bars radial distribution network with three different loading levels namely light (62.5%), nominal (100%), and heavy (125%) is used. Furthermore, the simulated results are contrasted with the previous research works to prove the effectiveness of the proposed methods. Keywords: Distributed Generation, Distribution Static Compensator, Optimal placement, Optimal sizing, Optimization, Radial distribution system.