Wakabayashi-ku (若林区) is the eastern ward of the city Sendai, in Miyagi Prefecture, Japan.

The area of present-day Wakabayashi-ku was part of ancient Mutsu Province, and has been settled since at least the Japanese Paleolithic period.

The area came under the control of the imperial dynasty during the late Nara period from their base at Tagajō.

During the Heian period, the Mutsu Kokubun-ji provincial temple was located in the area.

The ward also has two public high schools operated by the Miyagi Prefectural Board of Education.