This paper reports a first-ever cyclic voltammetric study and the electrochemical characterization of  Np(IV) complexes with task-specific ionic liquid with appended diglycolamide (DGA-TSIL) ligand dissolved in the room-temperature ionic liquid 1-butyl-3-methylimida-zolium bis(trifluoromethylsulfonyl)imide (C₄mimNTf2). The results are compared with molecular entity, N,N,N′,N′-tetraoctyl diglycolamide (TODGA) dissolved in the same diluent. The diffusion coefficient (D) values were determined using the Randles–Sˇevcik equation. The standard rate constant (k_s) values were also computed for the Np(IV)/Np(III) electrode redox reaction. The activation energy for diffusion (E_a) and thermodynamic parameters for the redox reactions of the Np complexes were determined and compared.