The best buses from Agadir to Marrakech are run by a company called Supra Tours.
Supra Tours is a subsidiary of ONCF, the national rail company. They run high quality air conditioned buses throughout the country.
Buses from Agadir for Marrakech depart several times a day from morning until evening, and are a great way to travel when visiting Morocco.
The total travel time from Agadir to Marrakech is 5 hours. Buses make a stop mid-way for a food and bathroom break.
Coaches fill up in advance, so consider buying your ticket the day before you travel. The cost of a single ticket on buses from Agadir to Marrakech is 80 to 90 Dh.