The Eighth Amendment of the Constitution Act 1983 was an amendment to the Constitution of Ireland which inserted a subsection recognising "the equal right to life of the pregnant woman and the unborn".

The Eighth Amendment (Amendment VIII) to the United States Constitution protects against imposing excessive bail, excessive fines, or cruel and unusual punishments.

The Eighth Amendment to the Constitution of Pakistan (Urdu: آئین پاکستان میں آٹھویں ترمیم) allowed the President to unilaterally dissolve the National Assembly and elected governments.