In this paper, we investigate the problem of finite-time guaranteed cost control of linear uncertain conformable fractional order systems. Firstly, a new cost function is defined. Then, by using some properties of conformable fractional calculus, some new sufficient conditions for the design of a state feedback controller that makes the closed-loop systems finite-time stable and guarantees an adequate cost level of performance is derived via linear matrix inequalities, therefore can be efficiently solved by using existing convex algorithms. | New results on finite - time guaranteed cost control of linear uncertain conformable fractional order systems