The yelkouan shearwater, Levantine shearwater or Mediterranean shearwater (Puffinus yelkouan) is a medium-sized shearwater in the seabird family Procellariidae. It was formerly treated as a subspecies of the Manx shearwater (Puffinus puffinus).

The yelkouan shearwater was formally described in 1827 by the Italian naturalist Giuseppe Acerbi from specimens collected in the Bosphorus, Turkey. He placed the shearwater in the genus Procellaria and coined the binomial name Procellaria yelkouan. The yelkouan shearwater is now placed in the genus Puffinus was introduced by the French zoologist Mathurin Jacques Brisson in 1760. The genus name Puffinus is Neo-Latin based on the English "puffin". The specific yelkouan is the Turkish word "wind chaser" for a shearwater. The yelkouan shearwater is considered to be monotypic: no subspecies are recognised.

It was formerly considered a subspecies of the Manx shearwater. After the first split, it was the nominate subspecies of the so-called "Mediterranean shearwater" for nearly ten more years; it is considered a monotypic species now, as the Balearic form mauretanicus has been separated as the Balearic shearwater.

A molecular phylogenetic study published in 2021 found very little genetic difference between the yelkouan shearwater and the Balearic shearwater (Puffinus mauretanicus). The authors of the study suggested that these two taxa might be better considered as subspecies of the same species.

The yelkouan shearwater appears to belong to a group of Mediterranean and adjacent Atlantic shearwaters which includes the Balearic shearwater and one to three prehistorically extinct taxa, Hole's and possibly also lava shearwater as well as an undescribed population of uncertain distinctness from Menorca. The two living Mediterranean lineages had probably separated before the end of the Pliocene (c. 2 million years ago), as indicated by molecular differences and the putative direct ancestor of the Balearic shearwater, the Ibizan fossil Puffinus nestori from the Late Pliocene or Early Pleistocene.

The yelkouan shearwaters is 30–35 cm (12–14 in) in length and has a wingspan of 70–84 cm (28–33 in). It has the typically "shearing" flight of the genus, dipping from side to side on stiff wings with few wingbeats, the wingtips almost touching the water. This bird looks like a flying cross, with its wing held at right angles to the body, and it changes from very dark brown to white as the dark upperparts and paler undersides are alternately exposed as it travels low over the sea.

It is silent at sea, but at night the breeding colonies are alive with raucous cackling calls, higher pitched and more drawn out than the Manx shearwater's.

The yelkouan shearwater has a more contrasted appearance than the Balearic shearwater with which its winter range overlaps, since the latter species is brown above and dirty white below. It is very similar to the black-and-white Manx shearwater of the Atlantic, and stray birds out of their usual range are very difficult to identify with certainty.