Nigerian novelist Chimamanda Ngozi Adichie has been awarded the 2018 PEN Pinter prize. She was hailed by Harold Pinter’s widow, the biographer Antonia Fraser, as a writer who embodies “those qualities of courage and outspokenness which Harold much admired”.

An award-winning novelist – her 2004 debut Purple Hibiscus won the Commonwealth writers’ prize, Half of a Yellow Sun won her the Orange prize in 2006, and Americanah took the US National Book Critics Circle award in 2014 – Adichie is also known for her TED talks and essays. Her most recent book is Dear Ijeawele, or a Feminist Manifesto in Fifteen Suggestions, which began as advice for a friend about how to raise her daughter as a feminist.

Her 2013 TED talk, We Should All Be Feminists, was later published as a pamphlet and distributed to every 16-year-old in Sweden as part of a campaign by the Swedish Women’s Lobby. Audio from the talk was also sampled by Beyoncé in her song ***Flawless.

The PEN Pinter prize is intended to honour a writer of “outstanding literary merit” who – in the words of Pinter’s speech on winning the Nobel prize in 2005 – casts an “unflinching, unswerving” gaze upon the world and shows a “fierce intellectual determination … to define the real truth of our lives and our societies”. Over the last decade, it has been won by writers including Margaret Atwood, Salman Rushdie and Tom Stoppard.

“I admired Harold Pinter’s talent, his courage, his lucid dedication to telling his truth, and I am honoured to be given an award in his name,” said Adichie.

Judges for the award praised Adichie’s “refusal to be deterred or detained by the categories of others”.

“In this age of the privatised, marketised self, Chimamanda Ngozi Adichie is the exception who defies the rule,” said Maureen Freely, chair of trustees for English PEN. “Sophisticated beyond measure in her understanding of gender, race, and global inequality, she guides us through the revolving doors of identity politics, liberating us all.”

Freely was joined on the judging panel by the writers Philippe Sands, Alex Clark and Inua Ellams, as well as Fraser.

Adichie will be awarded the prize on 9 October, when she will also announce her co-winner, the 2018 International Writer of Courage. Adichie will choose an author “who is active in defence of freedom of expression, often at great risk to their own safety and liberty”. Last year’s winner, the Belfast poet Michael Longley, shared the honour with the Iranian poet Mahvash Sabet.