The Chairman of the Electoral Committee, Mr Okey Amaechi (SAN), who declared the result in Abuja on Tuesday, said Alegeh polled 691 votes to defeat four other contestants.
Amaechi said the others were Mr Oladele Adesina (SAN), 370 votes, Mrs Olufunke Adekoya (SAN), 255 votes, Mr Adeniyi Akintola (SAN), 126 votes and Osas Erhabor, 17 votes.
Alegeh, who hails from Ikhabigbo, Etsako West Local Government Area of Edo State, holds Bachelor of Laws from the University of Benin and was called to the Nigerian Bar in 1986.
He equally attended Keble College, Oxford University, where he was awarded a Diploma in International Commercial Arbitration.
Alegeh was until his election the President, Chairman, Database and Documentation, Nigerian Lawyers Committee of the NBA as well as member, National Executive Committee of the NBA.
The president-elect and all newly elected officials will be sworn in at the NBA Annual General Conference in Owerri, between Aug. 24 and Aug. 29.