The Welsh Government's counsel general, or chief legal adviser, Jeremy Miles, will take charge of Wales' recovery from the Covid-19 pandemic.
First Minister Mark Drakeford said it represented "the biggest challenge we have faced as a devolved government".
He said Mr Miles would oversee co-ordination of work inside the Welsh Government to respond to the crisis.
As well as counsel general, Mr Miles is the minister dealing with Wales' transition from EU membership.
Mr Drakeford added: "This vital work will impact areas of Welsh peoples' lives; it will be profoundly important for public services, for the economy and society."