James Hillhouse (October 20, 1754 – December 29, 1832) was an American lawyer, real estate developer, and politician from New Haven, Connecticut.

From February to March 1801, Hillhouse briefly served as President pro tempore of the United States Senate.

[2] At the age of seven, he was adopted by his childless uncle and aunt, James Abraham and Mary Lucas Hillhouse.

[3][4] During the Revolutionary War, Hillhouse served as captain of the Second Company of the Governor's Foot Guard.

During the successful British invasion of New Haven on July 5, 1779, he commanded troops alongside Aaron Burr, with Yale student volunteers.

[7] During his time in this role, he administered the oath of office to Aaron Burr as Vice President, within the first inauguration of Thomas Jefferson on March 4, 1801.