Rhun ap Iorwerth has been elected unopposed as the new leader of Plaid Cymru, a month after the dramatic resignation of Adam Price.
He was the only candidate for the vacancy triggered by a damning report alleging bullying, harassment and misogyny.
The new leader said he was “committed to learning lessons” after a “difficult period”.
“Wales needs a strong Plaid Cymru,” he said.
The former BBC Wales journalist has represented Ynys Mon in the Senedd since 2013.
Plaid is the Welsh Parliament’s third largest party with 12 seats – it has three MPs in Westminster.
It is in a co-operation deal with the Welsh government, where Labour ministers have agreed to implement some of Plaid’s policies in return for votes in the Senedd.
First Minister Mark Drakeford welcomed the announcement and said he looked forward “to a constructive working relationship”.
Adam Price resigned as party leader after months of problems in Plaid Cymru.
He faced claims of a toxic culture in the party, while last November an allegation of sexual assault was made against a senior member of staff.
It led to the Project Pawb report by former Senedd member Nerys Evans, which found “too many instances of bad behaviour in the party”.
A Plaid Cymru Senedd member was separately suspended last year – pending an investigation – following a serious allegation about his conduct.
Rhun ap Iorwerth said he would “lead with passion; I will lead with humility”.
“Following a difficult period for the party, I am committed to learning lessons, implementing the recommendations of Project Pawb, and setting new foundations,” he said.
“My vision is one of a stronger, fairer economy able to support sustainable public services and allowing Wales to fulfil its real potential.
“Wales needs a strong Plaid Cymru if we are to build a confident nation working in partnership with others, but with its future firmly in its own hands.”
The Anglesey politician was the only candidate for the role.
That was despite former leader Leanne Wood saying the new leader should be a woman.
Shortly after her intervention on BBC Wales Live, the two remaining potential candidates ruled themselves out.