Born in Philadelphia, Pennsylvania. His father was a rope maker and Ord joined him in the business, continuing after his father’s death in 1806. In 1829 he retired from the business so that he could devote more time to science.
In 1815 he became a member of the Academy of Natural Sciences of Philadelphia, and two years later became a member of the American Philosophical Society. He went on to hold important positions in both. Ord received several of the specimens brought back by Lewis and Clark for description, including the Grizzly Bear and the American Bighorn Sheep.
He was friend and avid supporter of Alexander Wilson, accompanying him on several of his journeys. After Wilson’s death he finished the eighth and ninth volumes of Wilson's American Ornithology. He issued a life of Wilson in 1828 and published biographies of his fellow naturalists Thomas Say (1834) and Charles A Lesueur (1849). He also assisted in the enlargement of Samuel Johnson’s dictionary and the first edition of Noah Webster's dictionary. He was hostile to John James Audubon, whose drawings he disliked and who he felt was usurping the position of Wilson. He is buried in Philadelphia next to Wilson.