Kanagasabapathy Sripavan, 62, was sworn in on Friday, ending a crisis in the Supreme Court triggered by the sacking of former chief justice Shirani Bandaranayake two years ago.
Sripavan becomes the first Tamil to occupy the top judicial position in 24 years as Sri Lanka’s new leaders seek to mend ties with the country’s largest ethnic minority after a bloody 37-year war.
“Justice Sripavan was sworn in before President Sirisena,” the presidential secretariat said in a statement.
The appointment came two days after Sirisena declared the controversial impeachment of Bandaranayake by the previous government illegal, fulfilling one of the pledges he made before his surprise win in this month’s election.
Bandaranayake stepped down on Thursday, a day after being formally restored to the post, which she lost in January 2013 after angering former president Mahinda Rajapakse with her judgements against his administration.
Bandaranayake’s sacking was widely criticised, with the UN Human Rights Council calling it an assault on judicial independence.
The Supreme Court had been accused of political bias since she was replaced by Mohan Peiris.
The government of Sirisena, a member of the majority Sinhalese community, has vowed reconciliation with Tamils six years after the end of a separatist war that claimed at least 100,000 lives between 1972 and 2009.
The last Tamil chief justice was Herbert Thambiah, who left the position in 1991. (AFP)