Synthetic chemists have long standing goal of mimicking the hierarchical supramolecular assemblies of natural collagen proteins.^[1] Short synthetic collagen-mimetic peptides (CMPs) with repeating (Xaa-Yaa-Gly) triads have been explored to replicate such structures.^[2–5] However, so far investigated self-assembled structures of synthetic peptides suffer numerous challenges, with previous designs resulting in reduced thermal stability, formation of amorphous material, narrow range of concentration and buffer composition, and problem of phase separation. Further investigation is therefore essential to mine for new durable synthetic collagenous biomaterials. Recently, Li and coworkers showed that peptoid residues make diverse and hyper stable CMPs.^[6] Inspired by this seminal work, in our current study, we show that selective incorporation of peptoid residues with cationic N-Lys and anionic N-Glu type side chains in synthetic short CMP forms stable triple helical structure, which leads to the formation of hierarchical supramolecular assembly. We demonstrate that like Lysine and Glutamic acid residues present in natural collagen protein, cationic and anionic peptoid residues can be explored for manipulating ion pair interactions for designing well defined self -assembles of CMPs. We anticipate that our peptoid-modified CMP would be useful in designing new biomaterials for artificial tissue engineering.