Al-Mu'tamid (المعتمد al-Muʿtamid, d. October 892) was the Abbasid Caliph in Baghdad from 870 to 892 and eldest surviving son of al-Mutawakkil. He held the title of caliph for 23 years, though he was a largely a ruler in name only.
Al-Mu'tamid's brother, Al-Muwaffaq, had a claim to the throne and when the Zanj Rebellion started near Baghdad, al-Mu'tamid summoned al-Muwaffak to help him. From that point forward, Al-Muwaffaq essentially ruled as Caliph in all but name. After Al-Muwaffaq fell ill, he transferred substantial authority to his son, al-Mu'tadid. Al-Mu'tadid was popular in the capital, Baghdad, and al-Mu'tamid never regained any real power. In the year following his brother's death, al-Mu'tamid was obliged to publicly remove his own son from the succession and recognize al-Mu'tadid as his successor. He did not survive long thereafter;he drunk himself to death during a night festival in October 892, at the age of 50.
Al-Mu'tamid highest achievement may be the continuation of the era of prosperity that began with al-Muhtadi and lasted until the end of the century. However, the main cause of this prosperity was the return of the court in 892 to Baghdad, which curbed the power of Turkish soldiers. During al-Mu'tamid's reign and the two successive reigns, there were no assassination attempts upon the Caliph.