Niiro Tadakiyo served as a bushō in the early Edo period.  He was a retainer of the Satsuma domain.

In 1595, Tadakiyo was born as the eldest son of Niiro Tadamasu.

In 1583, his father’s older brother, Niiro Tadataka, died in battle at the age of thirty and, Tadataka’s lineal heir, Niiro Tadamitsu, died early in 1603.  Consequently, as the son-in-law of Tadamitsu, Tadakiyo inherited the headship of the clan.

Around the beginning of the Kanei era (1624 to 1644), Tadakiyo served as a senior magistrate and as the lord of the manor of Honjō in the Isa District of Satsuma.  In 1628, Tadakiyo succeeded his grandfather, Niiro Tadamoto, as the lord of the manor of Ōkuchi, serving in this role for the next twenty-seven years.  In 1637, at the Shimabara Rebellion triggered by opposition to the policies of the Edo bakufu to suppress Christians, Tadakiyo led forces from Ōkuchi on a deployment.  During a decisive battle, on 2/28, he took over Hara Castle.

In 1654, Tadakiyo died at the age of sixty.  Despite orders prohibiting martyrs, he was followed by three martyrs.