Thank you for your question.

According to this thread elsewhere on AskHistorians, there is contemporary evidence that the Apostle Paul existed, among other New Testament figures.

The thread contributors mention Clement of Rome, who was the third Bishop of Rome (some sources argue second). Clement is thought to have written the relevant epistle around 95 or 96 C.E. The letter's author refers to the martyrdom of Paul in Rome, and also mentions that the persecution which had led to the death of Paul happened "in our own time".

Source : Ehrman, Bart (2008). The New Testament: A Historical Introduction to the Early Christian Writings. Oxford University Press, USA. ISBN 978-0-19-532259-0. Pages 367 and 462 Fourth Edition.