Johann was born in Glasgow, Scotland, and raised in London. His father Eduard is a bus driver, and his mother Violet works in a refuge for victims of domestic violence. Having attended Woodhouse College he graduated with a double first in Social and Political Sciences at King's College, Cambridge in 2001.
He began his career as a staff reporter for the New Statesman in 2001, and has also been a columnist for the Evening Standard, London's newspaper. He is now a Senior Contributing Editor to Attitude, Britain's best-selling gay magazine, and he is a patron of the magazine Safer Society, which campaigns for more liberal and rehabilitative law and order policies.
His play, Going Down in History, was performed at the Garage Theatre, Edinburgh in 2002 to critical acclaim. His first book, God Save the Queen?, was published in 2003.
He was, in its first year, a supporter of the 2003 invasion of Iraq after visiting the country, because he believed anything would be better than Saddam, although he always argued the WMD rationale was false. Johann later wrote his support had been a 'terrible mistake' and he "should have known all along Bush would produce a disaster." He has subsequently been very critical of the occupation and of supporters of the war who still insist they were right. His post-war writings have been praised by Andrew Murray, Chair of the Stop the War Coalition, as "a tremendous service to the worldwide antiwar movement."
Prominent themes in his writing over recent years have included the plight of asylum seekers, refugees and detention centres and in 2004, Johann appeared as a guest on Richard Littlejohn's Sky News to debate the issue of exactly how much asylum seekers get in benefits, where he accused Littlejohn of being a "liar". Johann is critical of UK prison policies, claiming that rehabilitation is impossible in overcrowded prisons, and that far too many mentally ill people are incarcerated.
In 2007 he was named Newspaper Journalist of the Year by Amnesty International for his reporting on the war in Congo. The judges called his reports 'outstanding', 'beautifully written' and 'brave'. Johann has been nominated for many other awards, including Columnist of the Year at the British Press Awards, the Orwell Prize, the David Watt Prize and others.
Johann is a noted secularist and has recently been nominated for the Secularist of the Year Award by the National Secular Society and has also written in favour of free speech and against alternative medicine. He has defended rationalism and what he sees as enlightenment values, which he believes are under attack from several angles. A self-described antitheist, he has criticised Buddhism, Islam, Judaism and Christianity. He has criticised the Catholic Church's stance on birth control and Islamist attitudes towards women. He has been accused of Islamophobia, a charge he denies.He has also been critical of postmodernist views.
Johann has been called 'Maoist' by Nick Cohen, "Stalinist" by Noam Chomsky, 'Horrible Hari' by Niall Ferguson, "an uppity little queer" by Bruce Anderson, "a drug addict" by George Galloway, "fat" by the Dalai Lama and "a cunt" by Busted. Prince Turki Al-Faisal, the Saudi Ambassador to Britain, has accused Johann of "waging a private jihad against the House of Saud"
Johann, who is openly gay, supports gay rights, advocating full legal equality, including same-sex marriage. He has criticized radical gay theorists, and ideas of gay difference, superiority or separatism. He is a strong defender of the European Union and supported Britain joining the Euro.
Johann describes himself as a "European social democrat", who believes that markets are "an essential tool to generate wealth" but must be matched by strong democratic governments and strong trade unions. He is now based in Brick Lane, East London.