Nishi-ku (西区, Nishi-ku) was a ward in Hamamatsu, Shizuoka, Japan, located in the southwest corner of the city.

It is bordered by Naka-ku, Kita-ku, Minami-ku, and the city of Kosai.

The 3rd largest ward of Hamamatsu in terms of area, much of the ward is still rural, with farms and rice fields.

Nishi-ku was created on April 1, 2007 when Hamamatsu became a city designated by government ordinance (a "designated city").

International schools: This Shizuoka Prefecture location article is a stub.