The liberal Free Egyptians Party voted on Thursday for Essam Khalil to become its leader, a statement by the party said.
Khalil, a professor of mechanical engineering, received 421 votes in the party's general assembly while main rival Mohamed El-Bailey with 66 votes.
Born in 1948, Khalil is one of the founders of the party, which was formed in 2011.
He has been the acting chairman after the resignation of former leader Ahmed Saeid in 2014.
Five-hundred-and-one party members attended the general assembly to elect a new leader, including the co-founder and business tycoon Naguib Sawiris.
The Free Egyptians Party won 65 seats in the recent parliamentary elections. They will have the highest number of seats out of all parties in the House of Representatives that will covene for its first session on 10 January.