Murphy's Laws starting with O (28 laws)
- O'Toole's Commentary
- Old Engineer's Law
- Oaks's Unruly Laws for Lawmakers
- Oaks's Unruly Laws for Lawmakers
- Oaks's Unruly Laws for Lawmakers
- O'Brien's First Law of Politics
- O'Brien's Principle (The $357.73 Theorem)
- O'Brien's Rule
- Occam's Electric Razor
- Occam's Razor
- Occam's Razor Reformulations
- Occam's Razor Reformulations
- Occam's Razor Reformulations
- Oesner's Law (Oeser's Law)
