In a speech at the Presidential Palace, Moncef Marzouki said that despite some problems before it was approved, progress had been made to move the country forward.
“The new constitution embodies our hopes,” he said Monday to an audience including parliament members, political parties, members of non-governmental organizations and relatives of those killed in the January 14 Revolution.
Marzouki pointed out that a successful process had been conducted between different groups in the country.
Tunisia's 217-member National Constituent Assembly (NCA) approved the new constitution late Sunday - the first since the ouster of autocratic President Zine el-Abidine Ben Ali three years ago.
The vote was 200 in favor of the new charter, 12 against, with four abstentions.
It has been described as "a rare example of democracy in the Arab world", with the government adopting a "pluralist and participatory" approach.
Consisting of 10 chapters and 149 articles, its first articles address freedom and human rights.
The first chapter consisting of 20 articles state that the official religion is Islam, the official language Arabic, the form of government is republic, and all citizens are equal before the law.
Titled "Basic Rights and Freedoms," the second chapter states that it is the government's duty to protect people's basic rights and freedoms, and ensures the rights of citizenship and return.
The Constitution also guarantees that cases of torture may not be closed due to the passing of time.
The so-called Arab Spring, in which rebellions toppled regimes in Egypt, Libya and Yemen, began three years ago in Tunisia when mass protests overthrew Ben Ali.