The driving support device includes a line of sight detection unit that detects a line of sight of an occupant of the first following vehicle on the oncoming lane, a moving person estimation unit that estimates whether or not there is a possibility of a crossing moving person being present around the leading vehicle based on the detected line of sight, and a driving support unit that performs deceleration control of the host vehicle and the like when it is estimated that there is a possibility of a crossing moving person being present.