The Chemnitz–Adorf railway is a branch line in Saxony, Germany that was built and operated by the Chemnitz-Aue-Adorfer Eisenbahn-Gesellschaft (CAAE).

The 115 km long line originally ran from Chemnitz in a southwesterly direction along the valley of the River Zwönitz to Aue.

From Aue the line ran along the Zwickauer Mulde to Muldenberg and up to Schöneck and through Markneukirchen to Adorf in Vogtland.

In July 1872 the Chemnitz-Aue-Adorfer Eisenbahn-Gesellschaft gained the concession to build and operate a railway line from Chemnitz through Aue und Schöneck to Adorf in Vogtland.

On 24 December 1875 the complementary line, the 8 km long Zweigbahn from Zwotental to the Czech border at Klingenthal was opened.

But even in the first year of operation, the takings were below expectation and the company sold the line on 15 July 1876 to the Saxony government.

The Royal Saxon State Railways ran the line under the name CA (taking the letters from Chemnitz and Adorf).

Due to the unfavourable topology of the line, with long climbs and tight corners in the region of Lössnitz and Schöneck, made it unsuitable for heavy goods trains.

The short section between Aue und Zwönitz was known as the Sächsischer Semmering, the line climbed 255 m. In 1920 the Chemnitz-Aue-Adorfer railway passed to the newly formed Deutsche Reichsbahn.

From 1899 to 1970 a goods line ran from Zwönitz to Stollberg to bring the coal from the Oelsnitzer Revier in the Ore Mountains.

Only a short connecting line was needed from the CA-Linie to the town Eibenstock which was opened in 1905 and ran until 5 October 1975.

In 1975 the section between Wolfsgrün und Schönheide was permanently cut by the successful construction of the Talsperre Eibenstock reservoir.

Here the low floored trains run on tram lines through the city, both using the 1,435 mm (4 ft 8+1⁄2 in) standard gauge and adapting to the two power systems.

In Muldenberg the tracks take Vogtlandbahn running from Falkenstein and ascend to Schöneck on the crest of the Ore Mountains.