He is the first politician not from Labour to achieve this in the 27-year history of the Welsh Parliament.
Mr ap Iorwerth succeeds Baroness Eluned Morgan, who lost her seat in the recent Senedd election and resigned as Welsh Labour leader after poor results for the party.
Mr ap Iorwerth will seek to form a minority government after Plaid Cymru secured the largest bloc in the election, with 43 MSs but falling short of a majority.
His nomination was supported by the two Wales Green Party MSs, while Liberal Democrat MS Jane Dodds and Welsh Labour MSs abstained. The Senedd’s presiding officer will write to the King recommending his official appointment.
There were two other nominations for first minister: Reform’s Dan Thomas received 34 votes, and the Welsh Conservatives’ Darren Millar received seven.
Mr ap Iorwerth needed more support than all other candidates combined in order to win.
He described the result as the “greatest privilege” of his life, stating, “Something has stirred in the soul of Wales – a new confidence, a new hope.
“Something has stirred in the soul of Wales – a new confidence, a new hope, a new broader horizon, never to be narrowed again by the naysayers with other priorities in other places.”
He promised to lead without prejudice or presumption and paid tribute to Lady Morgan, who governed “with resilience and determination.”
Her defeat is noted as a “Portillo moment” in Welsh electoral history, marking her as the first serving leader of a government to lose her seat in British electoral history.
Ken Skates, Welsh Labour’s interim leader, expressed sadness over the party’s loss, stating that Welsh Labour in opposition would focus on serving the interests of the people.
Dan Thomas, leader of Reform Wales, which returned 34 MSs, stated his party would be a “robust opposition” to the Plaid Cymru government, emphasizing a pro-Union stance and commitment to blocking taxpayer funding for an independence commission.
