Polymerase is an enzyme catalyzing the polymerization of nucleic acids.

It is an accident of history that the enzymes and organelles responsible for the catalytic production of other biopolymers are not also referred to as polymerases.

One particular polymerase, that from the thermophilic archae, Thermus aquaticus (Taq, pronounce "tack") (PDB 1BGX, EC 2.7.7.7) is of vital commercial importance due to its use in the polymerase chain reaction, a widely used technique of molecular biology.