The red squirrel or Eurasian red squirrel (Sciurus vulgaris) is a species of tree squirrel in the genus Sciurus common throughout Eurasia. The red squirrel is an arboreal, omnivorous rodent.

In Great Britain, Italy and Ireland, numbers have decreased drastically in recent years. This decline is associated with the introduction by humans of the eastern grey squirrel (Sciurus carolinensis) from North America, In addition, habitat loss is a factor. Due to this, without conservation the species could disappear from those shores within a generation.