The pension age will rise sooner than expected, some incapacity benefits will be time limited and other money clawed back through changes to tax credits and housing benefit.
A new bank levy will also be brought in - with full details due on Thursday.
Mr Osborne said the four year cuts were guided by fairness, reform and growth.
But shadow chancellor Alan Johnson, for Labour, called the review a "reckless gamble with people's livelihoods" which risked "stifling the fragile recovery" - a message echoed by the SNP, despite smaller than expected cuts in Scotland.
Mr Osborne ended his hour-long Commons statement by claiming the 19% average cuts to departmental budgets were less severe than expected. This is thanks to an extra £7bn in savings from the welfare budget and a £3.5bn increase in public sector employee pension contributions.Read Full Story