The Polish-born pope led the Roman Catholic Church from 1978 until his death in 2005.
Pope Francis also approved the sainthood of Pope John XXIII (1958-1963), though no second miracle has been attributed to him.
A precise date for the canonisations will be set by a meeting of cardinals, the Vatican said.
John Paul II has been on a fast-track to sainthood since his death. Just six years later he was beatified by his successor Pope Benedict XVI.
Canonisation, the final step in declaring a deceased person a saint, requires a further miracle to be attributed to prayers to the candidate after they have been beatified.
An "inexplicable recovery" on the very day of John Paul II's beatification has been assessed as a miracle by the Vatican's saint-making department, the Congregation for the Causes of Saints, and Pope Francis has now approved that decision.