Thanks to the work of the National Dialogue Quartet, the North African nation last year adopted a new constitution and democratically elected a president, Beji Caid Essebsi, for the first time.
The award is a "tribute to martyrs of a democratic Tunisia", said the head of the UGTT union, part of the quartet which has not been active since the start of this year.
"This effort by our youth has allowed the country to turn the page on dictatorship," said Houcine Abassi, secretary general of the UGTT.
The quartet also includes the Tunisian Confederation of Industry, Trade and Handicrafts, the Tunisian Human Rights League, and the Tunisian Order of Lawyers.
Two years ago, amid the tumult unleashed by revolutions in the region, Tunisia's future was looking bleak.
The country was politically paralysed, threatening the entire democratic process triggered by the overthrow in January 2011 of dictator Zine El Abidine Ben Ali.
The killings of two opposition lawmakers Chokri Belaid and Mohamed Brahmi in 2013 shocked the nation.
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The Islamist Ennahda party, winner of the first post-revolution parliamentary elections in October 2011, was beset by divisions, and its critics were boycotting the work of the new constituent assembly and organising mass demonstrations.
The UGTT helped to put the troubled process back on track by bringing the different sides to the table.
The union was founded in 1946 by Farhat Hached, the nationalist leader who was assassinated in 1952, four years before Tunisia's independence.
With a membership of about half a million and a network of operations across the country, it is capable of organising large protests and strikes in response to social grievances.
It has a history of involvement in politics, even joining the ranks of the government after independence in 1956, before falling out with Tunisia's first president Habib Bourguiba.
Under Ben Ali, the UGTT was the country's only union, and the only national political force other than the former leader's own ruling party.
Its efforts are widely recognised among Tunisia's political class for having helped prevent a polarisation of society between Islamists and anti-Islamists and avoid the kind of chaos seen in other states shaken by Arab Spring uprisings.
In October 2014, the secular Nidaa Tounes party led by Essebsi came top in legislative polls conceded by Ennahda, and in December Essebsi won Tunisia's first free presidential election.
But Tunisia today still faces major challenges, notably jihadist violence that saw 21 tourists and a policeman killed in March at the Bardo museum in Tunis and 38 foreign tourists shot dead at a beach resort in June.