Systematics and the Origin of Species is a book written by zoologist and evolutionary biologist Ernst Mayr that was first published in 1942. The book became one of the canonical publications on the modern evolutionary synthesis.

Based on Mayr?s Jesup Lectures delivered at Columbia University in 1941, the book combines concepts of zoology and genetics and features Mayr's biological species concept. The biological species concept developed by Mayr defines a species in terms of biological factors such as reproduction, taking into account ecology, geography, and life history; it remains an important and useful idea in biology, particularly for animal speciation.

In December 2004 the National Academy of Sciences held a colloquium in honour of Mayr's 100th birthday. Systematics and the Origin of Species: On Ernst Mayr's 100th Anniversary was also published in commemoration.

pt:Systematics and the Origin of Species