A polymer-supported terpyridine Pd(II) complex was prepared and found to promote the Suzuki-Miyaura coupling reaction in water. Thus, terpyridine ligand was prepared from p-hydroxybenzaldehyde, propane sultone, and 2-acetylpyridine according to the reported procedures. Immobilization of terpyridine ligand onto a polystyrene-poly(ethylene glycol) (PS-PEG) resin through ionic bonds to sulfonate group took place and the complexation of PS-PEG-terpyridine ligand with Pd(II) underwent to give PS-PEG-terpyridine-Pd(II) complex. This polymeric catalyst showed high catalytic activity and high reusability for the Suzuki-Miyaura coupling reaction.