Tutong is a district (daerah) in Brunei and its capital is Pekan Tutong. Some major towns include Kuala Abang, Lamunin, Melit, Penanjong and Telisai.

The district borders the South China Sea to the north, the Bruneian district of Brunei and Muara and Malaysia to the east and the Bruneian district of Belait to the west. It has a population of 35,200, and covers 1,303km²/503mi².

The Sungai Tutong river flows through Tutong.

Tutong district is divided in 8 mukim (province), namely:Pekan Tutong ;Keriam ;Telisai ;

Tanjong Maya ;Kiudang ;Ukong ;Lamunin ;Rambai .

It has the largest lake in Brunei, Tasek Merimbun, which is declared as an ASEAN HeritagePark.