FORMER chief justice Arthur Chaskalson died in Johannesburg on Saturday, President Jacob Zuma said.
"Former chief justice Chaskalson passed away earlier today," he said in a statement.
"We wish the Chaskalson family strength during this difficult time. Our thoughts are with them."
He said Mr Chaskalson's life embraced a "courageous" role in the fight against apartheid, and in transitioning and shaping constitutional democracy.
"As the first president of our Constitutional Court he leaves a special imprint on the building of a united, non-racial, non-sexist constitutional democracy," said Mr Zuma.
"On behalf of all South Africans we reach out to his wife and family as we salute a life inseparable from South Africa's march to freedom.
The 81-year-old was battling leukaemia, according to the SABC.
Chaskalson served in the Constitutional Court from 1994, when he was appointed by former president Nelson Mandela.
He also served as chief justice of South Africa from November 2001 until his retirement in 2005.
During apartheid he represented members of the liberation movement in several major political trials, including the Rivonia Trial.
In his early years, Chaskalson graduated from the University of the Witwatersrand, according to the Constitutional Court website.
He helped establish the Legal Resources Centre, a non-profit organisation that used the law to pursue justice and human rights in the country.
Chaskalson was a member of the board of the faculty of law at the University of the Witwatersrand from 1979 to 1999, and served as an honorary professor of law at the university from 1981 to 1995.
He married Dr Lorraine Chaskalson and had two children, Matthew and Jerome.