John Alfred Poor (January 8, 1808 – September 6, 1871) was an American lawyer, editor, and entrepreneur best remembered for his association with the Grand Trunk Railway and his role in developing the railroad system in Maine.
He was the older brother of Henry Varnum Poor of Standard & Poor's, who was his partner in some business ventures.
John Poor was an articulate man standing 6 feet, two inches (1.9 m) tall and weighing over 250 pounds (110 kg).
He learned the geography and commerce of northern New England during travels as a young man; and developed an early appreciation for the potential of railroads.
His commanding presence was enhanced by early speaking experience as a teacher and attorney.
He had a unique ability to assemble the necessary resources to build early railroads, although he left the routine work of operations to others.