Gaius Suetonius Tranquillus (c. 69–140) wrote the following in his "Lives of the Twelve Caesars":

"As the Jews were making constant disturbances at the instigation of Chrestus, he (Claudius) expelled them from Rome"

A common objection to this passage is that "Chrestus" was a common name, not a title.  They say that if Suetonius was referring to Jesus, he would have called Him "Christus".  This is somewhat true, but we have very good reason to suppose that Suetonius merely misspelled "Christus" here (perhaps mistaking the title for a name) and was referring to Jesus.

One reason is that the "Chrestus" he is referring to seems to be someone he expects his audience to be somewhat familiar with.  He doesn't say "a man named Chrestus" or anything along those lines, just "Chrestus".  There is no record of someone by this name who was so well-known that Suetonius' audience would have recognized him by the name alone.  This makes Jesus, at the very least, the most likely candidate for being the one Suetonius was talking about.

He certainly may have been talking about someone else, but it's more likely than not that he was referring to Jesus here.  Even the Jewish Encyclopedia considers this a reference to Jesus (see its page on "Christian").