Resin-supported metal scavengers are interesting in the separation and purification of target organic compounds and solvents because they avail a suitable and facile material platform for the adsorption of metal ions, thus enabling successive recycling. Here, a mussel-inspired catechol-functionalised or tunicate-inspired gallol-functionalised polymer, which was tethered to the Merrifield resin containing self-reducing hydroxyl groups that could bind well with metal ions, was synthesised via reversible addition–fragmentation chain transfer polymerisation. The number of functional groups on the surface of the resin was quantitatively controlled by modulating the ratio of the monomer to the resin-attached chain transfer agent. The metal ion adsorption capacity, as well as removal ability of the resin in an aqueous solution, which increased with the increasing number of the dihydroxy and trihydroxy groups, was investigated employing silver, copper, zinc, magnesium, lead, and iron ions. The polytrihydroxystyrene-bearing resin exhibited better metal ion-scavenging performance compared with the polydihydroxystyrene-incorporated resin at the same grafting degree in an aqueous solution owing to the tridentate structure of the gallol group, which acted as a ligand in the synthesis of the metal complex. The developed resins demonstrated that the residual metal catalyst that was derived from synthesising the conjugated polymer can be successfully removed. • Polydihydroxystyrene (PDHS) or polytrihydroxystyrene (PTHS) was incorporated into microbeads. • Reversible addition-fragmentation chain transfer agents afforded mussel-inspired catechol or tunicate-inspired gallol groups. • Hydroxyl group-containing polymers were synthesised on commercial resins to avail many metal-ion-binding sites. • The successive adsorption/desorption of metals from the PDHS or PTHS-immobilised resins demonstrated its reusability. • The metal scavenger resin was used to remove the Cu catalyst after the click reaction of the block copolymers.