Pope Donus was Pope from 2 November 676 to his death in 678. He was the son of a Roman named Mauricius. Few details survive about the person or achievements of Donus, beyond what is recorded in the Liber Pontificalis.
Relations with Constantinople at the time of Donus' reign tended towards the conciliatory. On 10 August 678 the Emperor Constantine IV Pogonatus wrote to Pope Donus, "the most holy and blessed archbishop of our ancient Rome and the universal Pope," hoping to attract him to engage in negotiations with the Patriarch of Constantinople and the Monothelites. He ordered that Pope Vitalianus' name be put back in the Diptychs of those bishops in communion with Constantinople, an act which caused him a great deal of trouble from the Monothelites and the Patriarch Theodoros.
Donus' pontificate lasted one year, five months, and ten days. He died and was buried in St. Peter's Basilica on 11 April 678.