Leland v. Oregon, 343 U.S. 790 (1952), was a United States Supreme Court case in which the Court upheld the constitutionality of placing the burden of persuasion on the defendant when they argue an insanity defense in a criminal trial.

[1] This differed from previous federal common law established in Davis v. United States, in which the court held that if the defense raised an insanity defense, the prosecution must prove sanity beyond a reasonable doubt, but Davis was not a United States constitutional ruling, so only limited federal cases, but not state cases.

[2]: 17  Oregon had a very high burden on defense, that insanity be proved beyond a reasonable doubt.

[2]: 17 The defendant was convicted of killing a fifteen-year-old girl in Multnomah County.

The case claimed that the "statute in effect requires a defendant pleading insanity to establish his innocence by disproving beyond a reasonable doubt elements of the crime necessary to a verdict of guilty, and that the statute is therefore violative of that due process of law secured by the Fourteenth Amendment."