Marcus Ummidius Quadratus Annianus (138–182) was a Roman Senator and the nephew of the Emperor Marcus Aurelius. He was involved in an unsuccessful plot to assassinate his cousin the Emperor Commodus, which led to his execution afterwards.
Offices Quadratus Annianus held included legate to the proconsul of Africa, and consul ordinarius in 167 with the emperor Lucius Aurelius Verus.[1]