In the letter released on Monday to the head of Myanmar's military, Senior General Than Shwe, the 59 former leaders demanded Aung San Suu Kyi be released when her latest current term of house arrest ends on May 27.
The letter noted that she is "the world's only imprisoned Nobel Peace Prize laureate".
Kim and Lech Walesa, the former Polish president, have also won the prize.
The letter said the Myanmar opposition leader was "not calling for revolution in Burma, but rather peaceful, non-violent dialogue between the military, National League for Democracy, and Burma's ethnic groups."
"We call on the government of Myanmar to release Daw Aung San Suu Kyi unconditionally and to free all the remaining political prisoners," the letter said.
"We believe this would give a significant sign of the government's will to initiate a genuine and effective transition towards democracy."
The letter was co-ordinated by the Oslo Peace Centre, run by Kjell Magne Bondevik, the former prime minister of Norway.
Ban Ki-moon, the United Nations' secretary-general, has also demanded Aung San Suu Kyi's release.