Legal aid in the United States is the provision of assistance to people who are unable to afford legal representation and access to the court system in the United States. In the US, legal aid provisions are different for criminal law and civil law. Criminal legal aid with legal representation is guaranteed to defendants under criminal prosecution who cannot afford to hire an attorney. Civil legal aid is not guaranteed under federal law, but is provided by a variety of public interest law firms and community legal clinics for free or at reduced cost. Other forms of civil legal aid are available through federally-funded legal services, pro bono lawyers, and private volunteers.

Gideon v. Wainwright, 372 U.S. 335 (1963), was a landmark U.S. Supreme Court decision in which the Court ruled that the Sixth Amendment of the U.S. Constitution requires U.S. states to provide attorneys to criminal defendants who are unable to afford their own. The case extended the right to counsel, which had been found under the Fifth and Sixth Amendments to impose requirements on the federal government, by imposing those requirements upon the states as well.