The Works Constitution Act (German: Betriebsverfassungsgesetz, pronounced [bəˈtʁiːpsfɛɐ̯fasʊŋsɡəˌzɛt͡s] ^ⓘ), abbreviated BetrVG, is a German federal law governing the right of employees to form a works council.

In the Stinnes–Legien Agreement of 1918, during the collapse of the German Empire in the aftermath of World War I, an agreement was reached between trade union confederation leader Carl Legien and industrialist leader Hugo Stinnes, so that capital and labour would cooperate on an equal footing in all aspects of economic management. This was codified in the Weimar Constitution, §165. To implement this principle, in 1920 the legal predecessor Betriebsrätegesetz [de] (Works Councils Act) mandated consultative bodies for workers in businesses with more than 20 employees. All voting rights and work councils were, however, abolished by Hitler in 1933, and replaced with Nazi controlled management bodies.

After World War II and the defeat of fascism, work councils were revived by collective agreements promoted under the Control Council Law No 22 (Kontrollratsgesetz No. 22) of the Allied-occupying forces in 1946. This enabled unions to create work councils with binding participation rights and be tasked with enforcing union collective agreements.

Subsequently, the agreements for work councils were codified in the Works Constitution Act, passed on 11 October 1952 in West Germany. Trade unions in Germany wanted much more, including the formalisation of works council members as union representatives, and the expansion of the Coal Co-Determination Act [de] in all industries. The Works Constitution Act reserved 1/3rd of Supervisory Board seats for employee representatives, in contrast with 1/2 for the coal industry. Instead, the Conservative government emphasized in the law, the legal restrictions on works councils and their independence from trade unions.

In 1972 the Works Constitution Act was significantly updated, and largely forms the current basis of the law.^{[citation needed]} It strengthened works council power on the plant level, while subordinating works councils to trade union when it came to collective bargaining.

The 2001 reform was passed by the SPD-Green cabinet in June 2001. It expands the number of works council members released from work, introduces a simplified election procedure for small workplaces, increased participation rights in environment, anti-racism, retraining, promotion of secure job contracts and more flexibility in setting up alternative works council structures that match modern corporate structures. It expands women participation through gender quotas, new provisions for part-time works council members (many who are women) and acknowledges the tension of work and family life balance.

Twenty years later in 2021, the Betriebsrätemodernisierungsgesetz (Works Council Modernization Act) passed, expanding co-determination rights to include artificial intelligence in the workplace, a new framework for online/hybrid meetings of works council proceedings, expanded simplified election procedure and lowers the voting age to 16 years old.

The BetrVG is divided up into 132 different sections (§1 – 132) which are grouped in the following topics.