Hamamatsu (浜松市, Hamamatsu-shi) is a city located in western Shizuoka Prefecture, Japan. In September 2023, the city had an estimated population of 780,128 in 340,591 households, making it the prefecture's largest city, with a population density of 500/km² (1,300/sq mi) over the total urban area of 1,558.06 km² (601.57 sq mi).

Hamamatsu is a member of the World Health Organization's Alliance for Healthy Cities (AFHC).

The area now comprising Hamamatsu has been settled since prehistoric times, with numerous remains from the Jōmon period and Kofun period having been discovered within the present city limits, including the Shijimizuka site shell mound and the Akamonue Kofun ancient tomb.

In the Nara period, it became the capital of Tōtōmi Province.

During the Sengoku period, Hamamatsu Castle was the home of future shōgun Tokugawa Ieyasu.

Hamamatsu flourished during the Edo period under a succession of daimyō rulers as a castle town, and as a post town on the Tōkaidō highway connecting Edo with Kyoto.

After the Meiji Restoration, Hamamatsu became a short-lived prefecture from 1871 to 1876, after which it was united with Shizuoka Prefecture. Hamamatsu Station opened on the Tōkaidō Main Line in 1889.

The same year, with the establishment of the modern municipalities system, Hamamatsu became a town.