Has any formerly excommunicated person ever been canonized as a saint in Catholicism?

Question

Has any formerly excommunicated person who later repented been canonized as a saint after their death?

Answer 1

Some saints were accused of heresy. St. Alphonsus of Liguori, discussing the patience of persecuted saints, writes (True Spouse of Jesus Christ ch. 13, §3, EPUB ref:839.48):

All the saints have been persecuted in this world. St. Basil was accused of heresy before St. Damasus, Pope. St. Cyril of Jerusalem was condemned as a heretic by forty bishops, and was deprived of his see.

^{He continues with examples of saints accused of lesser sins than heresy.}

St. Joan of Arc was excommunicated by her local bishop.

Pope St. Marcellinus was deposed for having offered incense to idols (albeit out of fear*) but later recanted and was re-elected pope.

^{*St. Robert Bellarmine argues in Papal Error?: A Defense of Popes said to have Erred in Fatih that "Marcelinus neither taught something against faith, nor was a heretic, or unfaithful, except by an external act on account of the fear of death". Others may disagree.}

Answer 2

Has any formerly excommunicated person who later repented been canonized as a saint after their death?

There are a few cases that come close to fitting into the parameters of your question, but not totally exactly.

I know of at least one that comes very close, but I can not recall the particular circumstances at the moment.

However, other other individuals come very close!

Some saints have lived in the peril of excommunication. Even canonized saints have been acquainted with the formal censures of ecclesiastical authority.

Even St. Athanasius was condemned by several councils, and being deposed from his place as Pope of Alexandria, spent years in exile.

St. Columba was excommunicated in 562 by the synod of Teltown for allegedly praying for the winning side in an Irish War. The excommunication was later held to be an abuse of justice and the bishops in question removed their charge.

Saint Joan of Arc by Bishop Pierre Cauchon on 30 May 1431 (even though he allowed her Holy Communion before her immolation). She was fully reconciled to the Catholic Church at her Trial of Nullification in 1456.

St. Mary MacKillop by Bishop Laurence Sheil in 1871. Five months later, from his deathbed, Shiel rescinded the excommunication