The first bishop of Malta, St. Publius, is mentioned in Acts. He was not, of course, yet a bishop. And, of course, he is not a Knight of Malta.
Acts 28:8 Douay-Rheims
8 And it happened that the father of Publius lay sick of a fever, and of a bloody flux. To whom Paul entered in; and when he had prayed, and laid his hands on him, he healed him.
Here is his procession on his feast day in 2012. St. Publius is also venerated as Malta’s first martyr. I love the feast days in Malta.