Nazanin Zaghari-Ratcliffe has been recognised for bravery at the Magnitsky Human Rights Awards, saying it made her "heart melt" to have her seven-year-old daughter Gabriella accept it on her behalf at a ceremony in London.
The British-Iranian dual national has been detained for more than five years in Iran, accused of plotting to overthrow the Iranian government, which she and her supporters deny.
In May this year, she was sentenced to another year in prison on charges of spreading "propaganda against the system".
Zaghari-Ratcliffe won the award for Courage Under Fire. "Truly moving moment as we all fight for justice and freedom for her and her family," tweeted Bill Browder, head of the Global Magnitsky Justice Campaign.
"It means a lot to me and my cellmates at Evin prison that we are not forgotten," Gabriella said, reading out a statement from her mother. "It makes my heart melt to see my daughter now big enough to receive this award and to read these words."
"Thank you to all of you for walking next to us while we still need to do this fight, and for still reminding us that freedom is one day closer."
Richard Ratcliffe, Nazanin's husband, ended a 21-day hunger strike last Saturday. He has strongly criticised the British government for failing to make progress in securing her release.
Zaghari-Ratcliffe was employed by the Thomson Reuters Foundation, the charitable arm of the news agency, and was arrested as she was returning home to Britain after visiting family.
Rights groups accuse Iran of holding dual-nationals as bargaining chips for money or influence in negotiations with the West, something Tehran denies.
The Magnitsky Awards recognise "brave journalists, politicians and activists in the field of human rights and anticorruption". They are named after Russian lawyer, Sergei Magnitsky, who was killed in Russian police custody in 2009 after exposing government corruption.
Campaigning by his former client Bill Browder led to the US Magnitsky Act, which seeks to freeze assets and impose travel bans on human rights violators worldwide.
Among other awards, Maria Kolesnikova from Belarus was recognised as Outstanding Opposition Figure. A leading voice in the protest movement despite the Lukashenko regime's brutal repression, she tore up her passport to avoid deportation and was subsequently sentenced to 11 years in prison.
The Outstanding Investigative Journalist award went to Catherine Belton. "She has exposed the crimes of the Putin regime in ways that nobody has ever done before. She’s now paid a very dear price in their retaliation with multiple abusive libel suits," Bill Browder said in a tweet.