Yunus Özyavuz (born 17 August 1978), better known by his stage name Sagopa Kajmer or formerly known as DJ Mic Check and Silahsız Kuvvet (Turkish: [sɑgopɑ kɑʒmæɾ]), is a Turkish rapper, singer, songwriter, record producer, and DJ. He is the first and only rapper to have given concerts in all of 81 provinces of Turkey.

He was born in 1978 in Samsun and finished his primary and high school there. He then started working as a DJ in one of Samsun's local radio stations. In order to continue his education, he moved to Istanbul and studied Persian language and literature at Istanbul University. He claims his early musical influences were the African music of his father and the Italian music of his mother.

In 1998, he founded the hip hop band Kuvvetmira and started his career with his stage name "Silahsız Kuvvet". He featured in the compilation album Yeraltı Operasyonu as Silahsız Kuvvet in 1999. He later changed his stage name to Sagopa Kajmer and released an album with the same name Sagopa Kajmer in 2002. Following the release of the album, he released Bir Pesimistin Gözyaşları in 2004. Same year, he contributed to the soundtrack for the movie G.O.R.A.. He released another studio album Romantizma in 2005 and on 11 August 2005 found his own production company Melankolia Müzik. In 2006, he released the compilation album Kafile under the label Melankolia Müzik. On 1 August 2006, he married fellow rapper Kolera (Esen Güler). In 2007, they released their first mutual album İkimizi Anlatan Bir Şey. He released two more solo albums, Kötü İnsanları Tanıma Senesi (2008) and Şarkı Koleksiyoncusu (2009), before releasing another mutual album with Kolera, Bendeki Sen, in 2010. Since then, he has released four studio albums: Saydam Odalar (2011), Kalp Hastası (2013), Ahmak Islatan (2017) and Kağıt Kesikleri (2022).