Jonathan Ingersoll (April 16, 1747 – January 12, 1823) was a Connecticut politician of the late eighteenth and early nineteenth centuries.

Ingersoll was born on April 16, 1747, in Ridgefield in what was then called the Province of Connecticut, a part of British America.^[1] He was the son of Rev. Jonathan Ingersoll (1713–1778) and Dorcas (née Moss) Ingersoll (1725–1811).^[2] His father was the chaplain for the Connecticut Troops during the French and Indian War.^[3] His sister, Esther Ingersoll, was married to Lt. Ebenezer Olmsted.^[4]

His uncle was Jared Ingersoll Sr., a British colonial official, and his cousin, Jared Ingersoll, served as Attorney General of Pennsylvania. His cousin's son (his first cousin once removed), Charles Jared Ingersoll, was a U.S. Representative and the father of author Edward Ingersoll.^[5]

He graduated from Yale College in 1766 and began practicing as a lawyer.^[6]

From 1792 until 1797, he was a member of Connecticut council of assistants;^[2] he simultaneously served as a judge of the Connecticut Supreme Court of Errors from 1792 to 1798.^[7]

On September 16, 1793, he was elected as a member representing his state at-large in the United States House of Representatives, by a special election (to replace Congressman-elect Benjamin Huntington who had become a Judge). However he declined this office before the 3rd Congress convened, so he was never sworn in. A replacement was elected at a special election on November 11, 1793.^[8] He served as Superior court judge in Connecticut, 1798–1801 and 1811–1816.^[9]

Ingersoll was the ninth Lieutenant Governor of Connecticut from 1816 until his death in 1823.^[10]

On April 1, 1786, he was married to Grace Isaacs (1772–1850), the daughter of Ralph Isaacs, Jr., a Yale educated merchant who was prominent in New Haven and Branford. Together, they were the parents of:^[11]

• Grace Ingersoll (1787–1816), who married Peter Grellet and died aged 29 in Paris, France.^[6]
• Ralph Isaacs Ingersoll (1789–1872), a U.S. Representative from Connecticut who served as the U.S. Minister to the Russian Empire under President James K. Polk.^[12]
• Mary Ingersoll (1791–1842)^[13]
• William Isaacs Ingersoll (1793–1830)^[13]
• Charles Jared Ingersoll (1795–1795), who died in infancy.^[13]
• Charles Anthony Ingersoll (1798–1860), a United States federal judge nominated by President Franklin Pierce.^[14]
• Harriet Ingersoll (1798–1872)^[13]
• Jonathan Ingersoll (1803–1875)^[13]
• Edward Ingersoll (1809–1809), who died in infancy.^[13]
• Edward Ingersoll (1810–1883), an Episcopal minister in Buffalo, New York.^[15]

Ingersoll died while in office on January 12, 1823, in New Haven, Connecticut. He was buried in Grove Street Cemetery in New Haven.