There are three bands which come up under this name:
1) Instrumental dueling bass and drum trio hailing from NYC. http://www.leadernyc.net/
2) Pop punk band hailing from Brighton, UK
3)Dutch heavy/speed metal band who released their sole album "Out in the Wasteland" in 1988. The band split up in 1990.
4) Leader is also poprock band from Pilsen, Czech republic http://bandzone.cz/leader