Isaac Harding Duval (September 1, 1824 – July 10, 1902) was an adventurer and businessman prior to becoming a brigadier general in the Union Army during the American Civil War.

As a young man, he traveled to Fort Smith, Arkansas, where he joined an elder brother who was running a trading post.

He was a member of the Lopez expedition to Cuba that sought to aid the Cuban national independence movement.

After he recovered, he was promoted to the rank of brigadier general and given charge of a brigade of infantry in the VIII Corps.

By the end of the war, Duval had fought in 36 separate engagements and commanded two different divisions in the VIII Corps.