Mark 1:9

And it came to pass in those days, that Jesus came from Nazareth of Galilee, and was baptized of John in Jordan.

Cross-reference

Matthew 3:13-15 includes John's objection and Jesus' reply, expanding the baptism account in Mark 1:9.

Luke 3:21 notes Jesus' baptism among the people and his prayer, adding detail to Mark 1:9.