Madras ( /mædrəs/ mad-res) is a city in Jefferson County, Oregon, United States. Originally called The Basin after the circular valley the city is located in, it is unclear as to whether Madras was named in 1903 for the cotton fabric called "Madras" that originated in the Madras (now Chennai) area in India, or from the city of Chennai, then known as "Madras". The population was 5,078 at the 2000 census, with an estimated population of 6,640 in 2008. It is the county seat of Jefferson County.
Madras was incorporated as a city in 1911. An Army Air Corps base was built nearby during World War II. This airfield now serves as City-County Airport. Homesteads about 5 miles (8.0 km) north of the city on Agency Plains were based on dryland wheat.
According to the United States Census Bureau, the city has a total area of 2.2 square miles (5.6 km²), all of it land.