'''Medz Yeghern''' ({{lang|hy|Մեծ եղեռն}}, ''Mets yegherrn'' {{lit|GreatKejahatan Evil CrimeBesar}}) adalah istilah [[bahasa Armenia|Armenia]] untuk [[genosida]], khususnya genosida Armenia. Penggunaan istilah tersebut telah menjadi subyek kontroversi politik karena dianggap lebih ambigu daripada kata genosida.<ref>{{Cite news |first=Khatchig |last=Mouradian |url=http://www.armenianclub.com/2006/10/01/explaining-the-unexplainable-terminology-employed-by-armenian-media/ |title=Explaining the Unexplainable: The Terminology Employed by the Armenian Media when Referring to 1915 |work=The Armenian Weekly |date=23 September 2006}}</ref><ref>{{cite news |last1=Matiossian |first1=Vartan |title=The 'Exact Translation': How 'Medz Yeghern' Means Genocide |url=https://armenianweekly.com/2013/05/15/the-exact-translation-how-medz-yeghern-means-genocide/ |work=The Armenian Weekly |date=15 May 2013}}</ref><ref>{{cite journal |last1=Boghos Zekiyan |first1=Levon |title=Expulsion (tehcir) and genocide (soykırım): from ostensible irreconcilability to complementarity : thoughts on Metz Yeghern, the Great Armenian Catastrophe |date=2014 |url=http://157.138.8.12/jspui/handle/11707/5174 |language=en}}</ref> Istilah Հայոց ցեղասպանություն (''Hayots tseghaspanutyun''), secara harfiah "genosida Armenia", juga digunakan dalam konteks resmi, misalnya, [[Tsitsernakaberd|Հայոց ցեղասպանության թանգարան (Museum Genosida Armenia)]] di Armenia.
