Niwa Nagahide (丹羽 長秀, October 16, 1535 – May 15, 1585), also known as Gorōzaemon (五郎左衛門), his other legal alias was Hashiba Echizen no Kami (羽柴越前守), was a Japanese samurai of the Sengoku through Azuchi-Momoyama periods of the 16th century.

When he wasn't in battle, he was aiding Nobunaga's conquests by taking care of political affairs and had responsibility for constructing Azuchi Castle, which began in 1576 and was completed in 1579.

[2] In 1581, in a military parade held at Kyoto before the eyes of the Emperor as well as foreign missionaries, Nagahide was given the honor of leading the procession.

In 1582, as Oda Nobutaka's second in command, Nagahide launched a campaign on Shikoku, but before he made any progress, Nobunaga died during an attack by Akechi Mitsuhide.

Nagahide abandoned the campaign and turned back to join Hashiba Hideyoshi in avenging Nobunaga's death by killing Mitsuhide at the Battle of Yamazaki.

Later, at the subsequent meeting in Kiyosu Castle where the future of the Oda clan was discussed, Nagahide supported Hideyoshi's position.