The magnetohydrodynamic (MHD) flow of an electrically conducting fluid is studied in an array of identical parallel ducts stacked in the direction of external magnetic field and are separated by conducting walls of arbitrary thickness. Such arrangement of electromagnetically coupled ducts arises in fusion blanket applications in which a liquid metal is used both as coolant and tritium generation. The finite element method (FEM) with SUPG stabilisation is used for solving the set of coupled MHD equations. Numerical results show that, there is a significant effect of coupling the ducts with conducting walls of varying thickness, on the flow and induced current behaviours especially near the walls and for increasing values of Hartmann number. The results are presented for one, two and three coupled ducts in both coand counter-flow configurations which induce reversal and counter-current flows.