The youth-led protests against planned tax hikes started off peacefully but turned violent, killing at least 39 people in clashes with the police last month.
Some demonstrators briefly stormed parliament, before Ruto abandoned the new taxes.
"I will immediately engage in extensive consultations across different sectors and political formations and other Kenyans, both in public and private, with the aim of setting up a broad-based government," Ruto said in a televised address, adding that he would announce additional measures later.
He also dismissed the attorney general but said the office of the deputy president was not affected.
The sweeping cabinet changes were what Kenyans have been asking for, veteran anti-corruption activist John Githongo told Reuters.
Protests against tax increases hikes started off peacefully but escalated amid clashes with police. (EPA PHOTO)
"Let us see what happens now if the new ministers deal with big issues around corruption and just the arrogance and excess of his administration and the fact that a lot of Kenyans died during the demonstrations," he said.
"Hopefully this should temporarily calm things."
Ruto has been caught between the demands of lenders such as the International Monetary Fund (IMF) to cut deficits and a hard-pressed population reeling from rising cost of living.
Last week he proposed spending cuts and additional borrowing in roughly equal measure to fill the nearly $US2.7 billion ($A4.0 billion) budget hole caused by the withdrawal of the tax hikes.
Analysts have said the tax roll-back means Kenya is likely to miss IMF targets although the government does not have debts that are due.
The budget deficit is projected at 4.6 per cent of gross domestic product in the fiscal year that started on July 1.
Ojango Omondi, a community activist from the Social Justice Centres Working Group in Nairobi, said dismissing so many cabinet ministers was a "move towards justice" but activists would want to see who Ruto appoints in their place.
"It's one thing to dismiss, the second is to ensure that the people that will be chosen in the cabinet are accountable to the constitution and the rule of law," Omondi said.
