In corporate governance, codetermination (also "copartnership" or "worker participation") is a practice where workers of an enterprise have the right to vote for representatives on the board of directors in a company. It also refers to staff having binding rights in work councils on issues in their workplace. The first laws requiring worker voting rights include the Oxford University Act 1854 and the Port of London Act 1908 in the United Kingdom, the Act on Manufacturing Companies of 1919 in Massachusetts in the United States (although the act's provisions were completely voluntary), and the Supervisory Board Act 1922 (Aufsichtsratgesetz 1922) in Germany, which codified collective agreement from 1918.

Most countries with codetermination laws have single-tier board of directors in their corporate law (such as Sweden, France or the Netherlands), while a number in central Europe (particularly Germany and Austria) have dual boards.

The threshold of a company's size where co-determination must apply varies between countries: in Denmark it is set at 20 employees, in Germany over 500 (for 1/3 representation) and 2000 (for just under a half), and in France for over 5000 employees. Sweden has had a law of codetermination since 1980.