William Gardner Choate (August 30, 1830 – November 14, 1920) was a United States federal judge.
Born in Salem, Massachusetts, Choate received an A.B. from Harvard University in 1852 and an LL.B. from Harvard Law School in 1854. He was in private practice in Danvers, Massachusetts from 1855 to 1857, then in Salem, Massachusetts until 1865, and then in New York City from 1865 to 1878.
On March 14, 1878, Choate was nominated by President Rutherford B. Hayes to a seat on the United States District Court for the Southern District of New York vacated by Samuel Blatchford. Choate was confirmed by the United States Senate on March 25, 1878, and received his commission the same day. Choate served on the court for only three years, resigning on June 1, 1881.
He resumed his private practice in New York City from 1881 to 1920. He founded the Choate School (later Choate Rosemary Hall) in 1896, and from 1902 to 1903 he served as president of the New York City Bar Association.
He died in Wallingford, Connecticut.
A brother of William Choate, George C. S. Choate was the founder of a sanitarium in what is now part of Pace University's Pleasantville campus in Westchester County, New York, whose famous patient included politician and New York Tribune founder, Horace Greeley.