Tinja or Tindja (تينجة) is a town in northern Tunisia located at Lake Ichkeul. Its name derives from that of the ancient city of Thimida.
Attached administratively to the governorate of Bizerte, it is the seat of a delegation and a municipality of 17 454 inhabitants (2006) while the city itself is home to 11,219 inhabitants.

As Menzel Bourguiba which it is distant only four kilometers, Tinja is located in the isthmus separating the Ichkeul Lake and Lake Bizerte linked to the Mediterranean Sea. Its name comes from the river Tinja, which flows into the lake while a 5 km channel crossed a lock eponymous regulate the water exchange between the freshwater lake and saltwater lagoon. Indeed, the open sluice winter allows exchanges between the two media, particularly to maintain a sufficient degree of salinity of the lake to prevent the atrophy of fauna and flora. Fisheries are exploited at the channel.

An important industrial area is located and should benefit from the rehabilitation of the road between Tinja in Menzel Bourguiba who then joined Tunis-Bizerte motorway (A4)