The opposition Sam Rainsy Party has named Ke Sovannaroth, a Siem Reap parliamentarian, to replace its outgoing secretary-general, Eng Chhay Ieng.
Ke Sovannaroth said she hoped to strengthen the internal rules and leadership structure of the party "to push for internal unity and strengthen the party's work."
Eng Chhay Ieng resigned from the position after July's national election, where the Sam Rainsy Party took 26 National Assembly seats, following a spate of defections from members to the ruling Cambodian People's Party. He still holds a National Assembly seat for the opposition.
Ke Sovannaroth, who is the wife of lawmaker Yim Sovann, will be the first woman to hold the position, which manages all of the party's operations, from the top levels and grass roots.
She takes the position as the opposition prepares for provincial and municipal council elections next year.
Her priorities will be "to strengthen the party's leadership structure, promote opposition work, unite activists and supporters and democrats, and increase the confidence of the public," she said.
"She really has enough capacity and experience to lead the party to be popular and more active than before," party leader Sam Rainsy said. "She has known clearly the Sam Rainsy Party's structure and culture and has the ability to solve all the problems."