National Freeway 1 (Chinese: 國道1號; pinyin: Guódào Yīhào), also known as Sun Yat-sen Freeway (Chinese: 中山高速公路; pinyin: Zhōngshān gāosù gōnglù), is a turnpike in Taiwan, the first restricted controlled-access highway built in Taiwan. It begins in Keelung at the intersection of Xiao 2nd Road and Zhong 4th Road and ends in Kaohsiung at the intersection of Zhongshan 4th Road and Yugang Road, giving it a total length of 374.3 km (232.6 mi).

The Republic of China government named the controlled highway Sun Yat-sen Freeway in honor of Sun Yat-sen, the country's founding father.^{[citation needed]}

National Freeway 1 is a tollway where the amount charged varies by distance traveled, with vehicles being fitted with an electronic tag to facilitate toll calculation; the term "freeway" refers to "free of signal", and not free from charge. There are eleven toll stations on the turnpike.

The construction began in 1971. The north section between Keelung and Zhongli (now Zhongli District, Taoyuan) was completed in 1974, and the entire highway was opened in 1978. A 20.7 km (12.9 mi) viaduct on top of the freeway between Xizhi and Wugu was completed in 1997 in order to expand the capacity of the road.^{[citation needed]}

Saudi Arabia supported the construction of the highway by providing an interest free loan.

The 2019 Han Kuang Exercise featured takeoff and landing practice by Republic of China Air Force aircraft on the Huatan section of National freeway 1 in Changhua County.

The lanes in both directions are listed below.