He was born 1950 in Ankara, Turkey to the notable journalist and writer Çetin Altan as the first of two sons. His brother Mehmet Altan is also a journalist, writer and university professor of economy politics.
A working journalist for more than twenty years, he has served in all stages of the profession, from being a night shift reporter to editor in chief in various newspapers.
In addition to having written columns in several Turkish newspapers, including Hürriyet, Milliyet and Radikal, Altan has produced news programming for television. He worked as the editor in chief and lead columnist of Taraf, a daily Turkish newspaper, until he resigned from his post in 2012.
He was fired from Milliyet after writing a column on 17 April 1995 titled "Atakurd", which presented an alternate history of Turkey.
In September 2008 when Altan published an article titled "Oh, My Brother" dedicated to the victims of the Armenian Genocide, he was charged under Article 301 of the Turkish Penal Code for "denigrating Turkishness". The judicial claim was initiated by the far-right "Great Union Party."
During Turkey's media purge after the failed July 2016 coup d'état on September 23, 2016, Altan, was arrested. On 16 February 2018, along with his brother Mehmet and four others he was sentenced to life imprisonment with the condition that they be locked up for 23 hours each and every day.