Hattori Kazutada served as a bushō during the Sengoku and Azuchi-Momoyama periods.

Kazutada originated from Tsushima in Owari Province.  First, he served as an umamawari, or member of the cavalry, for Oda Nobunaga.  In the fifth month of 1560, at the Battle of Okehazama, Kazutada received the honor of being the first to attack Imagawa Yoshimoto, a sengoku daimyō and the eleventh head of the Imagawa clan based in neighboring Suruga Province.  As Yoshimoto attempted to fight back, Kazutada sustained an injury to his knee from the tip of Yoshimoto’s spear.  Mōri Shinsuke (later known as Mōri Yoshikatsu) assisted Kazutada and then followed-up by killing Yoshimoto and taking his head.  After the Battle of Okehazama, there is no information of notable achievements while Kazutada continued to serve under the command of the Oda clan.

On 6/2 of Tenshō 10 (1582), Nobunaga died in a coup d’ètat led by Akechi Mitsuhide in Kyōto.  This is known as the Honnō Temple Incident.  His younger brother, Hattori Kotōda, was killed during this incident at the Niji palace.  After the death of Nobunaga, Kazutada served as an umamawari for Toyotomi Hideyoshi and was chosen as a member of the kiboroshū, an elite unit of the cavalry who rode with yellow canopies to deflect arrows or other objects hurled at them in battle.

In 1585, Kazutada was invested with the court titles of Junior Fifth Rank (Lower) and Chief of the Bureau of Imperial Hostesses.  Owing to his contributions during the Conquest of Odawara, Gamō Ujisato, the lord of Matsusaka Castle in the Ichishi District of Ise Province, was transferred to Wakamatsu Castle in Aizu in Mutsu Province with a fief of 600,000 koku.  In 1591, Kazutada was appointed as the new lord of Matsusaka Castle with a fief of 35,000 koku.  At the same time, he was assigned to Hashiba Hidetsugu who governed Owari and northern Ise.

In 1592, during the Bunroku Campaign on the Korean Peninsula, Kazutada joined an advance to Hanseong.

In the seventh month of 1595, Kazutada was subject to a seizure of his landholdings on account of complicity in events resulting in the downfall of Toyotomi Hidetsugu.  After being turned over to the custody of Uesugi Kagekatsu, he was ordered to commit seppuku.  His second eldest son, Hattori Katsunaga, was adopted by Ōsaka Nagayuki, a retainer of Kimura Shigekore, a daimyō, who, similar to Kazutada, took his own life in connection with the downfall of Hidetsugu.  Katsunaga then served the Kishū-Tokugawa family.