Nagao Fusakiyo served as a bushō during the Sengoku period.  He was a retainer of the Yamanouchi-Uesugi family.

Fusakiyo was born as the third son of Nagao Sanekage.  His second older brother, Nagao Kagehito, was a retainer of Uesugi Fusaaki, the tenth head of the Yamanouchi-Uesugi family and deputy shōgun of the Kantō.  Fusakiyo received one of the characters in his name from the name of Fusaaki.

Kagehito inherited Fusakiyo’s original home of the Kamakura-Nagao clan so Fusakiyo inherited the Inugake–Nagao family, members of the Nagao clan.  In 1475, after the sudden death of his nephew, Nagao Sadakage, Sadakage’s younger brother, Nagao Kagenaga, became the successor but was in his youth so Fusakiyo served as his guardian.

According to a document from Ōta Dōkan, in 1477, during the Revolt of Nagao Kageharu, Fusakiyo allied with Nagao Kageharu and rebelled against Uesugi Akisada, the head of the Yamanouchi-Uesugi.

In the eleventh month of 1487, the Ōgigayatsu-Uesugi and Yamanouchi-Uesugi embarked on a full-scale conflict known as the Chōkyō War.  At this time, Fusakiyo colluded with Uesugi Sadamasa, the head of the Ōgigayatsu-Uesugi family leading to an attack by Uesugi Akisada on Kannō Castle in Shimotsuke Province.   In 1495, when Iwamatsu Naozumi (the lord of Nitta-Kanayama Castle in Kōzuke Province) and Yokose Narishige (a chief retainer) came into conflict, Fusakiyo led Ashikaga forces on a deployment in support of the Iwamatsu clan.

In 1504, Fusakiyo is said to have died at the Battle of Tachikawa-no-hara, but he was already dead at this time so there is a theory that this is confused with his son.