The Wallangarra Railway Station was first opened in February 1887 when the Queensland southern railway line was extended from Stanthorpe. Nearly a year later in January 1888, the New South Wales main northern line was extended from Tenterfield to Wallangarra.
Wallangarra Railway Station sits on the border of Queensland and New South Wales with a single island style platform, the border crosses the platform diagonally on the New South Wales end of the platform. The Queensland railway line comes in on the western side of the platform and the New South Wales railway line comes in on the eastern side of the platform.
The adjacent town Jennings in New South Wales is named after Patrick Jennings, the New South Wales Premier at the time. Wallangarra is an Aboriginal name, best thought to mean lagoon and made up of two words. Wallan meaning water and guran meaning long. Wallangarra was at times hyphenated as Wallan-Garra, the hyphen later removed.
The railway station initially had different names on each side with the New South Wales side named Jennings, the name of the town on the New South Wales side of the border. It was eventually changed to be consistent as Wallangarra on both sides of the railway platform 
after the different names caused confusion to travellers.
The separate lines coming in on different sides of the platform is due to the Queensland and New South Wales railway lines use different gauges. New South Wales uses a full-width gauge and Queensland uses a narrower gauge, making them incompatible so Wallangarra became the break-of-gauge railway station.
Originally, Jennings didn’t want the break-of-gauge station to be at Wallangarra as the proposal to build the railway station that New South Wales was to contribute towards was too expensive and there wasn’t much there. He proposed Tenterfield Railway Station 
to be the break-of-gauge station arguing that Tenterfield was an established town.
The Queensland government pushed ahead with building a cheaper railway station than first proposed at Wallangarra and New South Wales decided to extend the northern railway line from Tenterfield to Wallangarra.
The railway station at Wallangarra became the first Sydney to Brisbane railway line, even though the railway line was different gauges and required transferring of goods and passengers to continue the journey.
The importance of the Toowoomba-Wallangarra southern line diminished in the 1930s when the main northern line was replaced. The northern line in New South Wales from Grafton to Kyogle was extended through the Border Loop railway line to cross the Richmond Gap in 1930. The new railway line used a standard gauge all the way through to Brisbane, eliminating the need for a break-of-gauge railway station.
