Tani Moriyoshi served as a bushō during the Sengoku and Azuchi-Momoyama periods.

In 1529, Moriyoshi was born in the village of Ijira in Mino Province.  He was the son of Fukuda Rokubei-no-jō Masayuki (the younger brother of Fukuda Tsunamori).  Later, he was adopted by his uncle, Tani Tarōzaemon Tsunamori, who served Azai Sukemasa.

The Tani clan founded the Yamato-no-Aya clan.  At the time of the Jinshin Conflict in the seventh century, an ancestor named Tani 直監 served Emperor Tenmu, but Tani Takamori, an ancestor who died in 1441 during the Kakitsu Disturbance that resulted in the killing of Ashikaga Yoshinori (the sixth shōgun of the Muromachi bakufu), was a natural son of Ikeda Takakatsu of the Ōmi-Rokkaku clan.  The lineage of the family thereafter is traced to the Sasaki clan of the Uda-Genji.

Initially, Moriyoshi served Saitō Dōsan.  After the Mino-Saitō clan under Saitō Tatsuoki was extinguished in 1573, Moriyishi served Oda Nobunaga.  Owing to his contributions during the Ishiyama War, in the fifth month of 1576, he received a written commendation from Nobunaga.

Upon orders of Nobunaga, after Hashiba Hideyoshi became the commander-in-chief for operations in the western provinces, Moriyoshi became a yoriki, or security officer.  In 1578, he was granted a fief of 6,000 koku at Hirata Castle in Harima.

Moriyoshi participated in the assault on Miki Castle by Hideyoshi from 1579, and to sever the supply routes to Miki Castle, established a position on 賀伏坂 and, together with his son, Tani Moritomo, defended Hirata fortress.  On 9/10, Moriyoshi died in an attack by the Mōri forces led by Oishi Nakatsukasa Shōyū.  This occurred in the Battle of Hirata-Ōmura during the Siege of Miki.  He was fifty years old.

Moriyoshi was succeeded by his son, Tani Moritomo, who founded the Yamaga domain in the Edo period.