Period instruments, or playing on period instruments refers to performance of classical music on the original instruments of Renaissance, Baroque or Classicism, or using the historical replicas of the original instruments preserved in the museums.

A number of chamber music ensembles (known as early music ensembles) and period instrument orchestras (also known as Baroque orchestras) specializing in the music of Renaissance and Baroque perform on period instruments.

Another term that may be used is "on authentic instruments".