As with all of the original four he will re-spawn if he goes MIA (missing in action due to exceeding the 2.5km load distance in an atmosphere) or KIA (killed in action), this means that unless Jeb is stranded the player will constantly get Jeb for flights.

How long does it take for Kerbals to Respawn?

How long can kerbals respawn? It will respawn in few hours. You can wait until it respawns. For 1 hour, you can wait it.

How do you revive in Kerbals?

If you want them back to life immediately rather than waiting, you can open your KSP game folder/saves/username/persistent. sfs with your favorite text editor, find ROSTER and change the crew members' statuses from state = 3 to state = 0 . This will instantly revive your Kerbals.