thumb|right|The [[15-crown-5 crown ether, a cyclic oligomer, and its monomer, ethylene oxide.]]
In chemistry and biochemistry, an oligomer () is a molecule that consists of a few repeating units which could be derived, actually or conceptually, from smaller molecules, monomers. The name is composed of Greek elements oligo-, "a few" and -mer, "parts". An adjective form is oligomeric. Different heterogeneous and homogeneous catalysts are operative in producing green oils via the oligomerization of alkenes.
See also
- GPCR oligomer
- Oligomery (botany)
- Protein oligomer