Al-Beblawi served as finance minister in the cabinet of former prime minister Essam Sharaf, who resigned in November 2011, Xinhua reported.
ElBaradei, leader of the National Salvation Front, which is in opposition to ousted president Mohamed Morsi's administration, was the former head of the International Agency for Atomic Energy (IAEA).
Last week, Morsi was ousted by the army after millions of people took to the streets to protest his "poor performance" and "maladministration" since he took office a year ago.
The armed forces handed over power to Mansour, head of the Supreme Constitutional Court, to run the country for a transitional period.