Sovereign immunity (also known as governmental immunity) in American law was derived from the British common law doctrine that the King could do no wrong—and thus could not be sued. Sovereign immunity varies from state to state, but typically applies to state governments as well as the federal government.

For example, sovereign immunity protects the state and its various provisions of state government—including agencies, boards, hospitals, and universities—from liability and from suit—unless the immunity has been waived. Similarly, sovereign immunity protects political subdivisions—including counties, cities, and school districts—from liability and from suit—unless the immunity has been waived.

Thus, sovereign immunity encompasses two principles: (1) immunity from suit and (2) immunity from liability. Immunity from suit bars a suit against the state or other governmental entity unless the Legislature expressly gives consent. Immunity from liability protects the state or other governmental entity from judgments even if the Legislature has expressly given consent to sue.

In some states, when a governmental entity contracts, it is liable on contracts made for its benefit as if it were a private person. Consequently, when a governmental entity contracts with private citizens it waives immunity from liability. But the governmental entity does not waive immunity from suit simply by contracting with a private person. Legislative consent to sue is still necessary.

But federal and state governments (generally the U.S. Congress and state legislatures) have the ability to waive their sovereign immunity. Waivers of sovereign immunity are usually included in state and federal statutes and interpreted and applied by state and federal courts in court opinions.

A party may establish legislative consent by referencing a statute or a resolution granting express legislative permission. Legislative consent to sue the state or other governmental entity must be expressed in clear and unambiguous language.

In Ohio, sovereign immunity is a legal doctrine that protects the state government, its agencies, boards, hospitals, universities, and political subdivisions such as counties, cities, and school districts from being sued or held liable in certain circumstances. This immunity can be from suit, meaning that one cannot bring a lawsuit against the state without its consent, or from liability, meaning that the state may not be required to pay judgments even if consent to be sued has been granted. However, Ohio, like other states, can waive this immunity. The Ohio legislature has the authority to consent to such lawsuits through statutes or resolutions, which must use clear and unambiguous language to be effective. When the state or its subdivisions enter into contracts, they may waive immunity from liability, treating the government as a private party in terms of contractual obligations. However, immunity from suit is not waived merely by entering into a contract; explicit legislative consent is still required. Waivers of sovereign immunity are often found in state statutes and are interpreted by the courts.