James Alexander was a lawyer and statesman in colonial New York. He served in the Colonial Assembly and as Attorney General of the colony in 1721-1723. His son William was later a Major General in the Continental Army during the American revolution. Alexandria Township, New Jersey was named after James Alexander.

Alexander was born in Muthill in Pertshire, Scotland about 1690 to David Alexander ("of Muthil") . He entered the army and served as an Engineering officer. But, in 1714-1715 he joined the uprising in support of the Jacobite Pretender, and fled to America in 1715 when it failed. He settled in New York, and some time after his arrival in America, married a wealthy widow. His prior experience and political connections qualified him to become the surveyor for Perth Amboy, New Jersey in 1718. Shortly afterward he was appointed surveyor for New York and New Jersey and surveyed the boundary between New York and New Jersey. He was also appointed deputy-secretary of New York at about this time.

Alexander read law in New York and was admitted to the provincial bar of New Jersey in 1723. He served as Attorney General for the colony of New York from 1721 to 1723 and also served as Attorney General for New Jersey. He practiced law, engaged in mercantile pursuits, and built a considerable fortune. He also served many terms in the Colonial Assembly and was appointed to the Governor's Council. In 1725 he attempted to reform New Jersey's legal system to eliminate procedural delays. In 1727 he resigned as attorney-general of New Jersey.

Alexander was strongly opposed to New York Governor William Cosby. In 1732 Gov. Cosby succeeded through vigorous lobbying to have Alexander removed from the Council of New York. In 1733, Alexander started an anti-Cosby newspaper, the New-York Weekly Journal, with Peter Zenger as publisher. Critical editorials infuriated Cosby. The following year, Zenger was arrested on sedition charges, but eventually a jury acquitted Zenger in one of the first instances of jury nullification. Alexander and William Smith served as Zenger's attorneys until both were disbarred after they challenged the commissions of the judges hearing the case. In 1735 Alexander was removed from the Council of New Jersey as well.

Alexander was in less disfavor after Cosby's death in 1736. When Lord De La Warr was appointed governor in 1737, he was reinstated. He was readmitted to the bar and was reappointed to the governor's Council of New York. His removal from the Council of New Jersey was disregarded. Alexander became a vocal proponent of the emerging Whig political views, and engaged in various civic efforts as well. In 1743 he joined Franklin and others in founding to American Philosophical Society. In 1751 he raised funds to establish King's College.
Although he remained active in politics, his legal practice eventually absorbed most of his time and energy, and his political involvement waned. However, in 1756 he traveled to Albany to confer with other Whig leaders and to oppose a measure that would have proven onerous to the people of New York. He suffered a flare up of his gout which led to a deterioration of his health. He came home ill as a result and died in Albany or New York City on April 2, 1756.