Block Out was a Serbian alternative rock band formed in Belgrade in 1990. They were one of the most notable acts of the 1990s Serbian rock scene.
Originally formed under the name Ad Hoc, the band was initially hard rock-oriented, but moved towards darker, heavier sound with the arrival of guitarist and songwriter Nikola Vranjković in 1991, who would become the creative core of the band. The band's albums Crno, belo i srebrno, Godina sirotinjske zabave and San koji srećan sanjaš sam featured a combination of alternative rock, grunge, metal and psychedelic sound, with Vranjković's poetic and dark lyrics about Serbian society in the years following the dissolution of Yugoslavia and artistic music videos created by the band's vocalist Milutin Jovančić "Mita". In 2004 the band released their last studio album, Ako imaš s kim i gde. Despite critical acclaim and large popularity, growing disagreements inside the band led to Vranjković being excluded from Block Out in 2013. Vranjković started a successful career as a solo artist and the rest of band members continued to perform as Block Out for a short period of time, before continuing their work under the name Čovek Vuk.