- Madsen v. Women's Health Center, Inc.
- Mahan v. Howell
- Maher v. Roe
- Mainstream Loudoun et al. v. Board of Trustees of the Loudoun County Library et al.
- Mallory v. United States
- Malloy v. Hogan
- Manton v. United States
- Mapp v. Ohio
- Marbury v. Madison
- Marsh v. Alabama
- Marsh v. Chambers
- Martin v. Hunter's Lessee
- Martinez v. Bynum
- Maryland v. Craig
- Maryland v. Garrison
- Maryland v. Wilson
- Maryland v. Wirtz
- Massachusetts Board of Retirement v. Murgia
- Massachusetts v. Bangs
- Massachusetts v. Oakes
- Massachusetts v. Sheppard
- Mathews v. Eldridge
- Maxwell v. Dow
- McCleskey v. Kemp
- McCray v. United States
- McCulloch v. Maryland
- McGrain v. Daugherty
- McIntyre v. Ohio Elections Commission
- McKeiver v. Pennsylvania
- McLaurin v. Oklahoma State Regents for Higher Education
