Melodic death metal (also referred to as melodeath and MDM) is a subgenre of metal which adds melody to the intensity of death metal. Gothenburg metal, a subset of melodic death metal that originated in the Swedish city in the early '90s, helped popularize the genre and has been a huge influence on the genre as a whole. Originally, the genre combined the harmony style and groove melodies of heavy metal with the harsh thrashing sound and vocals of death metal. Early melodic metal bands seem to have taken lots of influence from American bands.

Melodic death metal contains more melodic guitar riffs, melodic solos and acoustic guitar work than traditional death metal. It also contains more comprehensible lyrics with traditional death growl and screaming vocals. The pioneers of melodic death metal include Ceremonial Oath, Carcass, Dark Tranquillity, At the Gates and In Flames. Sentenced is also sometimes credited as one of the first melodic death metal bands with their release of North from Here. Some melodic death metal bands combine the genre with other metal genres such as progressive metal (e.g. Into Eternity), power metal (e.g. Children of Bodom), symphonic metal (e.g. Eternal Tears of Sorrow), thrash metal (e.g. Arch Enemy), doom metal (e.g. Swallow the Sun) and folk metal (e.g. Eluveitie).

In the late 1990s, many melodic death metal bands changed their style of playing by adding more melodic elements; more melodic choruses and riffs and making more prominent use of keyboards. Also many melodic death metal bands moved away from the lyrical themes of death, gore and murder common in other death metal groups.