We report a mild, iridium-catalyzed borylation of aromatic polysulfone with bis(pinacolato)diboron [B-2(pin)(2)] to form the corresponding borylated polysulfones up to high concentrations with nearly constant efficiency. The Suzuki-Miyaura cross-coupling reactions of the borylated polysulfones with functionalized aryl bromides allows installation of various functional groups such as ketone, amine, hydroxyl, and aldehyde to the polysulfone main chain in excellent conversion.