President Mamnoon Hussain administered swore in Justice Tassaduq Hussain Jillani after Iftikhar Muhammad Chaudhry stepped down a day earlier.
Prime Minister Nawaz Sharif, Chaudhry and other top government officials including ministers attended the ceremony.
Legal circles see the 64-year-old Jillani to be a far quieter presence.
Jillani has been a Supreme Court judge since 2004 and, like Chaudhry, was sacked when Musharraf imposed emergency rule in November 2007.