Is there any evidence for Jesus outside the Bible?

Yes - and some of it comes from writers who had no reason to help the Christian cause. Historians don't rely only on the New Testament to conclude that Jesus of Nazareth really lived.

The Roman historian Tacitus, writing around AD 116, records that "Christus" was executed "at the hands of the procurator Pontius Pilate" during the reign of Tiberius - a hostile source confirming the crucifixion. The Jewish historian Josephus, writing in the 90s, mentions Jesus twice; his longer passage was later embellished by Christian copyists, but scholars widely accept an authentic core, and his separate reference to "James, the brother of Jesus who was called Christ" is essentially undisputed. Pliny the Younger, a Roman governor around AD 112, describes early Christians gathering to worship Christ "as to a god." Lesser references appear in Suetonius, Lucian, and Mara bar-Serapion.

None of these writers were sympathetic to Christianity - which is exactly what makes them valuable. When an enemy or a neutral observer confirms a fact, it carries more weight than a friend's testimony. Together they independently attest that Jesus lived in the early first century, was known as a teacher with a following, and was executed under Pontius Pilate.

This is why the theory that Jesus never existed at all is rejected across the scholarly spectrum. Bart Ehrman - an agnostic New Testament scholar, not a believer - wrote an entire book, Did Jesus Exist?, rebutting the idea. As he puts it elsewhere, Jesus "certainly existed, as virtually every competent scholar of antiquity, Christian or non-Christian, agrees."

One honest note: these sources establish that Jesus lived and was crucified. They don't, by themselves, prove the resurrection - that case rests on the empty tomb, the early eyewitness testimony, and the transformation of the disciples. But the extrabiblical evidence firmly closes the door on the idea that Jesus is a legend with no historical footprint.