National Highway No. 1 (traditional Chinese: 中山高速公路; pinyin: Zhōngshān gāosù gōnglù) is the first freeway in Taiwan. It begins in Keelung City at the intersection of Siao 2nd Road and Jhong 4th Road and ends in Kaohsiung City at the intersection of Jhongshan 4th Road and Yugang Road, giving it a total length of 372.8 km. The Republic of China government named the freeway as Jhongshan (Chung-shan) Expressway in honor of Sun Yat-sen.

The construction began in 1971. The north section between Keelung City and Jhongli City was completed in 1974, and the entire highway was opened in 1978. A 20.7 km viaduct on top of the freeway between Sijhih and Wugu was completed in 1997 in order to expand the capacity of the road.