President Rajapaksa enjoys the support of more than two-thirds of the 225-member Parliament. Lawmakers voted 155 to 49 on Friday to impeach her. Twenty lawmakers, including four from the ruling party who disagreed with the impeachment, were absent.
The impeachment also drew international concern.
The United States Embassy in Colombo said it was deeply concerned by the proceedings.
"This impeachment calls into question issues about the separation of powers in Sri Lanka and the impact of its absence on democratic institutions," it said in a statement.
Sam Zarifi, Asia-Pacific director for the Geneva-based International Commission of Jurists, said the impeachment has "thrown into chaos the entire system of checks and balances in the country."
"As an immediate matter, this has precipitated a legal and constitutional crisis of unprecedented dimensions," he said in a statement.
Bandaranayake, who had long been viewed as pro-government, faced the allegations after she issued a ruling against a law promoted by a member of Rajapaksa's family.
The government is largely controlled by the Rajapaksas, including the president's older brother Chamal Rajapaksa, the speaker of Parliament. Two more brothers run the ministries of defense and economic development. One of the president's sons is a member of Parliament.
The impeachment set off a series of protests and rallies.
The bar association called a two-day strike Thursday. Association Secretary Sanjaya Gamage said any action to ignore the Supreme Court ruling could bring a "negative and eroding impact" on the rule of law. The lawyers hoisted black flags in courts in protest Friday.
Some 200 lower court judges also joined the strike.
Meanwhile, hundreds of government supporters gathered outside Parliament on Friday to back the impeachment and set off fireworks when they heard the outcome of the vote.
Associated Press writer Bharatha Mallawarachi contributed to this report.