The first wave of black metal (or old school black metal) refers to those bands during the 1980s who influenced the black metal sound and formed a prototype for the genre. They were often speed metal or thrash metal bands. Venom's album entitled Black Metal inspired the name of the genre.

Actually, old school black metal is any heavy / speed / thrash metal music sounding similar to black metal, but lacking guitar riffing style developed in 1989-91 by Norwegian Mayhem and Thorns. Old school black metal sound bears more thrashy, punky guitars.

Noticeable examples:
* Venom (United Kingdom)
* Hellhammer (Switzerland).
* Bathory (Sweden) - first three or four albums
* Sarcófago (Brazil), and also their countrymen: Vulcano, Holocausto, Sextrash etc
* Sigh (Japan)
* Tormentor (Hungary)
* Blasphemy (Canada)
* Цербер (USSR)
* Von (USA)
* Bulldozer (Italy)
* Beherit (Finland)
* Master's Hammer (Czechoslovakia)
* Mayhem (Norway) - early demos

Also one can refer to as to old school black metal - some old thrash metal bands: Slayer, Sodom, Destruction, Kreator, Sepultura and many others.

Sometimes 80's black metal is divided into "the first wave" - more heavy / speed metal oriented bands (Venom, Mercyful Fate etc) and "the second wave" (Bathory and their followers), but it's more likely to hear of "the second wave" as of Norway's bands.