Shimofusa (下総町, Shimofusa-machi) was a town located in Katori District, Chiba Prefecture, Japan.

On February 11, 1955, it merged with the villages of Takaoka and Komikado to form the town of Shimofusa.

On March 27, 2006, Shimofusa, along with the town of Taiei (also from Katori District), was merged into the expanded city of Narita, and thus no longer exists as an independent municipality.

Its total area was 32.00 square kilometres (12.36 sq mi).

Shimofusa High School (千葉県立下総高等学校) is located in the former town.