In the biblical account of Noah's Ark, the dove brought an olive leaf back to Noah on its second flight.
Genesis says Noah sent the dove again after its first return. This time, the bird came back in the evening with a freshly plucked olive leaf in its beak. The sign showed Noah that the waters had receded enough for vegetation to appear above them.
The sequence includes a third release: the dove did not return, indicating that it had found places to live outside the ark. The olive leaf therefore functions as an intermediate sign, between the uncertainty of the earlier flight and the final evidence that the land was habitable.
The image of a dove carrying an olive branch became a widely recognized symbol of peace and hope. Strictly speaking, Genesis says “olive leaf,” while later art and popular language frequently use “olive branch.”