William Henry Law (September 11, 1803 – March 27, 1881) was an American politician.

Law, third son of the Hon. Lyman Law, and grandson of the Hon. Richard Law, was born in New London, Connecticut on September 11, 1803. His mother was Elizabeth Learned Law, daughter of Amasa Learned.

He graduated from Yale College in 1822. He studied law with his father, in New London, and after his admission to the bar, in 1826, practiced there until 1830. He then retired from his profession, and in 1832 removed to Norwich, Connecticut, which he represented the same year in the Connecticut General Assembly. In 1868 he removed to New Haven, Connecticut, where he died, March 27, 1881 at age 77.

In February, 1829, he married Mary Lee, of Norwich, who died in October, 1839, leaving them one daughter. In October 1855 he married Harriet B. Mills, of Mississippi, who survived him with one son, a graduate of Yale in the class of 1878.

 This article incorporates public domain material from the 1881 Yale Obituary Record.