Due process is a right defined in both the Fifth and Fourteenth Amendments to the U.S. Constitution. Both state that no person shall be "deprived of life, liberty or property without due process of law." The Fifth Amendment states that the federal government shall not deny these rights, and the Fourteenth Amendment extends the rights to the state-level.
Procedural due process refers to the specific rules that the state and federal government must follow when adjuticating civil and criminal cases. This includes providing neutral and unbiased court processes, rights to present evidence and call witnesses, a right to representation by council, and a right to see to the opposing side's evidence, among others.
United States ex rel. Vajtauer v. Commission of Immigration (1927)
Mullane v. Central Hanover Bank and Trust Co. (1950)
Substantive due process is the notion that, beyond legal cases, the Constitution protects fundamental rights from government interference. Over time, this has included things such as the right to work an ordinary job, the right to marry, the right to raise one's children as a parent, and the right to make medical decisions about one's body, among others.
Myer v. State of Nebraska (1923)
Pierce v. Society of Sisters (1925)
Griswold v. Connecticut (1965)
Cruzan v. Director, Missouri Dept. of Mental Health (1989)
Planned Parenthood of Southeastern Pennsylvania v. Casey (1992)
Washington v. Glucksberg (1997)
Dobbs v. Jackson Women's Health Organization (2022)
The definitions in this section are adapted from Cornell Law School Legal Information Institut's Wex.