Cui bono? (Classical Latin: [kui̯ ˈbɔnoː]), in English "to whom is it a benefit?", is a Latin phrase about identifying crime suspects. It depends on the fact that crimes are often committed to benefit their perpetrators, especially financially.

The phrase is a double dative construction. It can also be rendered as cui prodest? ("whom does it profit?") and ad cuius bonum? ("for whose good?").

Cicero himself used the expression Cui bono in his 'Second Philippic', once again invoking Cassius as the source: "... adopt that maxim of Cassius: To whose advantage was it?"^[2]

American sociologist Peter Blau has used the concept of cui bono to differentiate organizations depending on who has primarily benefited: owners; members; specific others; or the general society.^[3]

• Cherchez la femme
• Follow the money
• Milgram experiment
• Whodunit

General:

• Brocard (law)
• List of Latin phrases
• List of legal Latin terms