Farnesene interpolymer comprises units derived from a farnesene (e.g., α-farnesene or β-farnesene) and units derived from at least one vinyl monomer. The farnesene interpolymer can be prepared by copolymerizing the farnesene and at least one vinyl monomer in the presence of a catalyst. In some embodiments, the farnesene is prepared from a sugar by using a microorganism. In other embodiments, the at least one vinyl monomer is ethylene, an α-olefin, or a substituted or unsubstituted vinyl halide, vinyl ether, acrylonitrile, acrylic ester, methacrylic ester, acrylamide or methacrylamide, or a combination thereof.