The 3rd Rhode Island Infantry Regiment was an infantry regiment in the Union Army during the American Civil War.

Moved to Fort Monroe, Virginia, October 12–14.

It was attached to Sherman's South Carolina Expeditionary Corps.

Participated in the expedition to Port Royal, South Carolina, October 28-November 7.

The 3rd Rhode Island Infantry ceased to exist on December 19, 1861, when it was changed to 3rd Rhode Island Heavy Artillery.