In law, a conviction is the verdict that results when a court of law finds a defendant guilty of a crime.

The opposite of a conviction is an acquittal (i.e. "not guilty"). In Scotland and in the Netherlands, there can also be a verdict of "not proven", which counts as an acquittal.

For a host of reasons, the criminal justice system is not perfect, and sometimes guilty defendants are acquitted, while innocent people are convicted. Appeal mechanisms mitigate this problem to some extent. An error which results in the conviction of an innocent person is known as a miscarriage of justice.

After a defendant is convicted, the court determines the appropriate sentence as a punishment. Furthermore, the conviction may lead to results beyond the terms of the sentence itself. Such ramifications are known as the collateral consequences of criminal charges.

A minor conviction is considered, in a term, a warning conviction, and it doesn't affect the defendant, but does serve as a warning.

An accused's history of convictions are called antecedents, known colloquially as "previous" in the United Kingdom, and "priors" in the United States and Australia.