There are no direct flights to Harar. The nearest airport is in Dire Dawa, from where you can catch a minibus to Harar.
The bus station is near Harar Gate. Minibuses run frequently to Dire Dawa (Birr20, one hour) and Babille (Birr12, 45 minutes). There are also frequent buses to Jijiga (Birr42, 1½ hours).
For Addis Ababa (Birr300, nine to 10 hours), Sky Bus and Selam Bus depart around 5am from their ticket offices on the north side of the main road to Addis Ababa, between Harar Gate and Ras Makonnen Circle. The minibuses that do the capital run are less comfortable and more dangerous than the buses, but they do travel faster and they’ll pick you up at your hotel. You can book minibus tickets departing for Addis with Adil Transport. You can also buy tickets from your hotel, but you’ll pay a commission. Most minibuses leave between 4am and 2pm.