As the name implies, a Galilean was a native or inhabitant of Galilee which is located in northern Israel (see map below, and Bible Places). In New Testament times, their accent of Hebrew and Aramaic was apparently different than of Jews in the south, making them readily distinguishable when they traveled down to Judea. "Galilean" was used in a contemptuous way for early Christians, as was also the term for inhabitants of Nazareth (see Fact Finder below) which was in Galilee. Jesus Christ was a Galilean, as were nearly all (Judas Iscariot was one who wasn't) of The Twelve Apostles.
Galilee In The New Testament
After Jesus was arrested on The Fateful Night, Peter was identified as a Galilean, which resulted in his famous denial of Christ "before the cock crows," exactly as Jesus Christ said would happen.
"And as Peter was below in the courtyard, one of the maids of the high priest came; and seeing Peter warming himself, she looked at him, and said, "You also were with the Nazarene, Jesus."
"But he denied it, saying, "I neither know nor understand what you mean." And he went out into the gateway."
"And the maid saw him, and began again to say to the bystanders, "This man is one of them." But again he denied it."
"And after a little while again the bystanders said to Peter, "Certainly you are one of them; for you are a Galilean. But he began to invoke a curse on himself and to swear, "I do not know this man of whom you speak." And immediately the cock crowed a second time. And Peter remembered how Jesus had said to him, "Before the cock crows twice, you will deny Me three times." And he broke down and wept." (Mark 14:66-72 RSV)
Pontius Pilate discovered that Jesus Christ was a Galilean, and reported it to Herod Antipas (see The Herods) who was tetrarch of Galilee during much of Jesus' human life. Unlike his father Herod The Great, who had tried and failed to have Jesus killed when He was an infant, Herod Antipas saw the Christ killed.
"Then the whole company of them arose, and brought Him before Pilate. And they began to accuse Him, saying, "We found this man perverting our nation, and forbidding us to give tribute to Caesar [see Tiberius], and saying that He Himself is Christ a king."
"And Pilate asked Him, "Are you the King of the Jews?" And He answered him, "You have said so."
"And Pilate said to the chief priests and the multitudes, "I find no crime in this man." But they were urgent, saying, "He stirs up the people, teaching throughout all Judea, from Galilee even to this place."
"When Pilate heard this, he asked whether the man was a Galilean. And when he learned that he belonged to Herod's jurisdiction, He sent him over to Herod, who was himself in Jerusalem at that time."
"When Herod saw Jesus, he was very glad, for he had long desired to see Him, because he had heard about Him, and he was hoping to see some sign done by Him." (Luke 23:1-8 RSV)
Fact Finder: What was meant by the Biblical term "Nazarene"?