SON-9 (NATO reporting name Fire Can) is a type of Russian/Soviet fire director radar for air defence guns including the 57 mm, 85mm,[1] and 100 mm, and 130mm anti-aircraft guns.

[3][4] The SON-9 was widely employed during the Vietnam War, with as many as 75 of them being deployed at one point.

[4] Its range of 50 nautical miles was considered useful but the lack of a moving target indicator on the viewing scope complicated the task of tracking fast-moving, low-flying targets.

It was also more vulnerable to jamming than newer designs available during the Vietnam War.

[5] A captured example of the SON-9 was used by NOTS (Naval Ordnance Test Station) engineers to develop simulator SON-9 radars for training against.