The main purpose of this paper is to study the regional controllability concept of a semi-linear time-fractional diffusion system involving Caputo derivative of order α ∈ (0, 1). The main result is obtained by using an extension of the Hilbert Uniqueness Method (HUM) in addition to a fixed point technique and under several assumptions on the data of the considered equation. At the end, some numerical simulations are given to illustrate the efficiency of our result.