Aitzaz Ahsan, a former Member of Parliament and cabinet minister under assassinated former Prime Minister Benazir Bhutto, was detained under emergency powers that Musharraf invoked on Nov 3.
"He was released last night," Ahsan's wife, Bushra, said in Lahore.
"He's very upbeat about life. He's very happy. He has gone to Lahore High Court to address the bar."
Ahsan, president of the Supreme Court Bar Association, was held at Adiala Jail in Rawalpindi for nearly three weeks before being transferred to house arrest in Lahore.
He rose to prominence last year when he acted as chief counsel for Iftikhar Chaudhry, the Supreme Court chief justice whom Musharraf tried to sack last March.
Chaudhry's suspension whipped up a campaign against Musharraf by lawyers and opposition activists.
That culminated in Musharraf's declaration of an emergency, when Chaudhry and dozens of other judges seen as hostile to then army chief Musharraf's October re-election by legislators were purged.
Chaudhry and several other judges remain under house arrest.