A systematic study was carried out to explore the electrochemical behaviour of Ce in an EMIES ionic liquid at a glassy carbon (GC) electrode over the range 298–351 K. The electrode reaction of Ce^III/Ce^IV was found to be quasi-reversible by cyclic voltammetry. An increase in the current intensity was obtained with an increase in temperature. The diffusion coefficients (D_o), the transfer coefficients (α) of Ce^III and the charge-transfer rate constants (k_s) were estimated. The apparent standard potential (E⁰*) and the thermodynamic properties of the oxidation of Ce^III to Ce^IV were also investigated. A photoluminescence investigation on cerium extracted in EMIES ionic liquid shows the stabilization of cerium in the Ce^III state. There is a broad band at 350 nm, which is attributed to the 5d¹→4f¹ transitions. With an increase in temperature the Ce^III peak intensity decreases gradually and is almost flattened at 350 K. This may be a result of Ce^III being converted into Ce^IV with an increase in temperature and then not being luminescence-active as it is an f⁰ system.