He replaces Loic Faussier, who resigned for personal reasons after being with the bank for three years as CEO and in other key positions.
Long, 58, has accounting and law diplomas from two Hanoi universities and been working in finance-banking for 30 years.
He joined SeABank in 2005 as deputy CEO in charge of credit and risks management.
The executive board of SeABank now has nine members.
SeABank was established in 1994 and has 181 branches across the country.