who of the famous tzaddikim had non jewish ancestors or were born from non jewish mothers?

Shalom, Thank you for your question. There are many righteous and important Jews who were themselves converts, or whose ancestors were converts (there is even a Wikipedia page called “List of converts to Judaism”). We could start with Yitro, Moshe’s farther in law, who according to many opinions converted. Of course, there is Ruth, from the Tanach. In the Talmud we find Rabbi Akiva, who came from a family of converts. The Rabbis mentioned in the Mishna in the Ethics of our Farthers – Rabbi Hey Hey and Rav Bag Bag were converts. Here is a link to an article from Chabad that mentions 18 famous converts - https://www.chabad.org/library/article_cdo/aid/4098800/jewish/18-Amazing-Converts-to-Judaism-You-Should-Know.htm Blessings.