Born in Port Harcourt, Nigeria, to a Nigerian mother and the Jamaican novelist and poet Lindsay Barrett, A. Igoni Barrett studied agriculture at the University of Ibadan. In 2007 he moved to Lagos, where he met his wife, the Dutch journalist and writer Femke van Zeijl.
His first book, a collection of short stories entitled From Caves of Rotten Teeth, was published in 2005 and reissued in 2008. A story from the collection, "The Phoenix", won the 2005 BBC World Service short story competition.
His second collection of stories, Love Is Power, or Something Like That, was published in 2013; according to the Boston Globe, the collection "pulses with an indomitable life force that is, by turns, tender and fierce". Time Out New York commented: "These rich pieces are also brilliantly sequenced.... Shifts in mood happen throughout the book.... Unlikely moments of empathy occur again and again amid wrenching drama and subtle comedy; the resulting collection satisfies on numerous levels." Love is Power, or Something Like That was chosen as a "best book of 2013" by NPR and Flavorwire.
His debut novel, entitled Blackass, was published in 2015. Reviewing it in The Financial Times, Jon Day wrote: "From the first sentence, Kafka’s The Metamorphosis confronts you with the inherent strangeness of the pact you make when you read fiction. Gregor Samsa has become an insect, Kafka says. Suspend your disbelief. Take it or leave it. A Igoni Barrett’s first novel — his third book — demands a similar response....to read him only as a Nigerian writer would be to do him a disservice. For Blackass is a strange, compelling novel, and Barrett has something to tell us all." Writing in The Guardian, Helon Habila said: "Igoni Barrett’s greatest asset is his ability to satirise the ridiculous extents people, especially Lagosians, go to in order to appear important." Claire Fallon for the Huffington Post concluded: "Blackass is a blunt, transparently written novel — the kind that makes the reader feel as though they’re standing inside the skin of the character, going about his day with him — and though the topic could easily be that of a polemic, it’s also a subtle, circumspect novel about the intersecting, sometimes mutually exclusive needs humans have for family and connection, and for status and power." Aaron Bady of OkayAfrica calls it "the most unapologetically Nigerian book that American publishers have published in a long time, and as the 'Afropolitan' has become an increasingly omnipresent strand of contemporary African literature, there has been a steady backlash, both against the Afropolitan as such, and against the entire category of African immigrant literature. The novel was longlisted for the inaugural FT/OppenheimerFunds Emerging Voices Awards.
Invited as a participant to various literary festivals, Barrett was a guest reader on the opening night of the PEN World Voices Festival in 2013. He was the founding organizer of the BookJam reading series in Lagos, Nigeria, which featured the writers Jude Dibia, Michela Wrong, Chimamanda Ngozi Adichie, Binyavanga Wainaina, Helon Habila and Tsitsi Dangarembga, among others.
Barrett's work has appeared in many publications, including AGNI, Al Jazeera English and Electric Literature.
Igoni Barrett was a winner of the BBC World Service short story competition for 2005 with a story entitled "The Phoenix", which was broadcast on 2 January 2006.
In 2010, he was awarded a Chinua Achebe Center Fellowship. In 2011, he was awarded a Norman Mailer Center Fellowship as well as a Bellagio Center Residency.
In April 2014 Barrett was named as one of 39 sub-Saharan African writers aged under 40 in the Hay Festival and Rainbow Book Club Africa39 project celebrating Port Harcourt UNESCO World Book Capital 2014.
In December 2016 he was named on a list of "100 Most Influential Nigerian Writers Under 40 (Year 2016)" published on the Nigerian Writers Awards website.From Caves of Rotten Teeth: A Collection of Short Stories, Daylight Media Services, 2005, ISBN 9789780193591
Love Is Power, Or Something Like That: Stories, Graywolf Press, 2013, ISBN 9781555976408
Blackass, Chatto & Windus, 2015, ISBN 9780701188566; Graywolf Press, 2016, ISBN 978-1-55597-733-7.