Flavius Josephus published a history of the Jews in twenty books around 93 CE. The following passage is found in the extant Greek manuscripts of Josephus (Ambrosianus in the 11th century, Vaticanus in the 14th century, and Marcianus in the 15th century). This passage was also quoted by Eusebius in the fourth century: in the Evangelical Demonstration 3.5, in the Ecclesiastical History 1.11, and in the Theophany.

"Now there was about this time Jesus, a wise man, if it be lawful to call him a man, for he was a doer of wonderful works, a teacher of such men as receive the truth with pleasure. He drew over to him both many of the Jews, and many of the Gentiles. He was the Christ; and when Pilate, at the suggestion of the principal men amongst us, had condemned him to the cross, those that loved him at the first did not forsake him, for he appeared to them alive again the third day, as the divine prophets had foretold these and ten thousand other wonderful things concerning him; and the tribe of Christians, so named from him, are not extinct to this day."

But there is some controversy as to whether Josephus actually wrote this, or if it was added by later transcribers.

Whilst there's always room for more discussion, this is one of the more common questions at AskHistorians, and you can find a few prior discussions on this topic in our FAQ. The brief summary of those answers would be yes, historians are confident in the existence of an historical Jesus.