This follows Ali Belhadj's arrest last year for praising Iraq's insurgency despite being barred from making public statements.
Belhadj, the group's former deputy leader, went to visit his mother's grave at the Kuba cemetery after his release on Monday, his brother Abdelhafid told reporters.
Belhadj's mother died while he was in the al-Harrach prison in a suburb of Algiers.
Belhadj was one of 2200 Islamist prisoners being pardoned or having their sentences reduced as part of the Algerian government's effort to turn the page on the brutal insurgency that left about 150,000 people dead in the 1990s, his brother said.
Belhadj was barred from political or charitable activity and from making public statements when he was released in 2003, after serving a 12-year term for threatening national security.
Belhadj, a charismatic preacher, refused to sign the order condemning himself and fellow Salvation Front leader Abassi Madani to silence.
Still, it was considered legally binding.
Last July, Belhadj praised the Iraqi anti-government uprising on Aljazeera television and condoned the kidnapping in Iraq of two Algerian diplomats, who were later killed.
The Salvation Front rose to power in Algeria's first multiparty national elections in December 1991.
About 2200 prisoners are being
freed as part of peace efforts
The army cancelled the second round of the vote, igniting an insurgency that ravaged the country.
Tens of thousands of civilians were killed.
Government security forces were accused of playing at least a passive role in some of the bloodshed, which largely ended with a cease-fire in 1997.
As part of national reconciliation efforts approved in a referendum last year, jails around the country started releasing prisoners this weekend.
The plan foresees pardons for people convicted of crimes that did not involve massacre, rape or explosions in public places.