I can only name 3 Fathers who are said to have believed in Universal salvation, St Issac, St Gregory of Nyssa, and St Maximos - but I could not get any proof that St Maximus really believed it.
Apokatastasis still exercises its fascination on Eastern Christians, although it is not an approved belief. In the first centuries it seems to have been widespread among Christians. Saint Augustine tells us that it was a widely held early Christian belief."Some, nay, very many" (nonnulli, quam plurimi), pity with human feeling, the everlasting punishment of the damned, and do not believe that it is so."
~St Augustine. Enchiridion
, chapter 112.
That Catholic site I referenced earlier has a list of about 12-15 Church Fathers who supported universal salvation...... I don't know how reliable it is though.
And an interesting quote from Saint Martin of Tours which backs up Saint Augustine's statement that in the early Church there was a belief in the possibility of universal salvation, even including for the devil.“If thou, thyself, wretched being, wouldst but desist from attacking mankind, and even, at this period, when the day of judgment is at hand, wouldst only repent of your deeds, I, with a true confidence in the Lord, would promise you the mercy of Christ.
Martin preaches Repentance even to the Devil.
Now, the devil, while he tried to impose upon the holy man by a thousand injurious arts, often thrust himself upon him in a visible form, but in very various shapes. For sometimes he presented himself to his view changed into the person of Jupiter, often into that of Mercury and Minerva. Often, too, were heard words of reproach, in which the crowd of demons assailed Martin with scurrilous expressions. But knowing that all were false and groundless, he was not affected by the charges brought against him. Moreover, some of the brethren bore witness that they had heard a demon reproaching Martin in abusive terms, and asking why he had taken back, on their subsequent repentance, certain of the brethren who had, some time previously, lost their baptism by falling into various errors. The demon set forth the crimes of each of them; but they added that Martin, resisting the devil firmly, answered him, that by-past sins are cleansed away by the leading of a better life, and that through the mercy of God, those are to be absolved from their sins who have given up their evil ways. The devil saying in opposition to this that such guilty men as those referred to did not come within the pale of pardon, and that no mercy was extended by the Lord to those who had once fallen away, Martin is said to have cried out in words to the following effect: “If thou, thyself, wretched being, wouldst but desist from attacking mankind, and even, at this period, when the day of judgment is at hand, wouldst only repent of your deeds, I, with a true confidence in the Lord, would promise you the mercy of Christ.”
O what a holy boldness with respect to the loving-kindness of the Lord, in which, although he could not assert authority, he nevertheless showed the feelings dwelling within him! And since our discourse has here sprung up concerning the devil and his devices, it does not seem away from the point, although the matter does not bear immediately upon Martin, to relate what took place; both because the virtues of Martin do, to some extent, appear in the transaction, and the incident, which was worthy of a miracle, will properly be put on record, with the view of furnishing a caution, should anything of a similar character subsequently occur.
Source :: Sulpitius Severus "On the Life of St. Martin" Chapter XXI