The following are a few miracles from the life of the Saint that don't appear in many of the hagiographies. They are amateur translations and summaries from the full life found in the service of the Saint in Greek here: http://voutsinasilias.blogspot.com/2008/12/17.html.
For a few miracles of the Saint after his death, see: http://full-of-grace-and-truth.blogspot.com/2009/08/transfer-of-relics-and-selected.html.
May St. Dionysios intercede for us all and help us!
Selected Miracles from the Life of St. Dionysios of Zakynthos
One day the Saint wished to go from the monastery of Anaphonetrias to a place for some task, he said to his deacon Daniel [who was from Trikala of the Peloponese, and was ordained by the Saint and who remained in his synodeia] “get ready Daniel, let’s go to that place.” He replied, “Most-holy Despota, [Master: the traditional Orthodox greeting for a bishop] it looks like it is going to rain.” The Saint told him, “Let’s go to the glory of God, and don’t be an obstacle.” And after they had not gone too far from the monastery, it began to rain. The deacon said, “My Despota, didn’t I tell you it would rain? It’s better to turn back, because it is raining a lot and over-flowing.” But this man of God told him “Let’s go forward and nothing will happen to us.” And as the time passed, the rain increased even more. But O Your wonders O Lord! With all of the incredible rain, neither the archpriest’s nor the deacon’s clothes got soaked. And reaching a roaring river, over which they had to cross, and seeing it increased because of the rain that day, the deacon said to the Saint in wonder “and how, my Despota, will we now pass over this river?” Then the Saint with boldness replied, “Follow me in the name of Jesus Christ, and don’t hesitate at all.” The deacon therefore followed in obedience, and going forth from there [O paradoxical marvel] the current of the river stopped, raised up in one and another place, until the two passed over without their feet in any way touching rock. Then, the Saint seeing his deacon amazed by these incredible wonders, told him not to reveal this to anyone while the Saint lived. After the Saint’s death he revealed this clearly to the glory of God.
(prayer at the end of the Synaxarion)