Our chemical exploitation of saturated macrocyclic polyamines has led to discoveries of numerous new functions, and synthesis of new functional molecules and supramolecular complexes. In this account, we focus on 1) anion complexes with biologically relevant polyanions at neutral pH; 2) uptake of selective transition metal ions by new peptide-mimic amide-containing macrocyclic polyamines; 3) specific complexation with noble metal ions; 4) the first fluorinated macrocyclic polyamines; 5) macrocyclic polyamines with new functional pendants; 6) stabilization of unusually high oxidation states of transition metal ions (e.g. Cu^III, Ni^III), and uptake and activation of O₂ by the Ni^II-peptide-mimic macrocyclic complexes; 7) zinc enzyme models by Zn^II-macrocyclic polyamine complexes; 8) selective recognition of a nucleobase thymine (and uracil) in nucleic acids by Zn^II-12-membered macrocyclic tetraamine (“cyclen”) complexes; and 9) new supramolecular assemblies from Zn^II-cyclen building blocks in aqueous solution.