Joseph Hooker (November 13, 1814 – October 31, 1879) is a career United States Army officer, achieving the rank of major general in the Union Army during the American Civil War.

Although he serves throughout the war, usually with distinction, Hooker is best remembered for his stunning defeat by Confederate General Robert E. Lee at the Battle of Chancellorsville in 1863.

After graduating from the United States Military Academy in 1837, Hooker serves in the Seminole Wars and the Mexican-American War, receiving three brevet promotions.

Resigning from the Army in 1853, he pursues farming, land development, and (unsuccessfully) politics in California.

After the start of the Civil War he returns to the Army as a brigadier general.

He distinguishes himself as an aggressive combat commander leading a division in the Battle of Williamsburg, May 5, 1862, resulting in his promotion to major general.

As a corps commander, he leads the initial Union attacks at the Battle of Antietam, in which he is wounded.

At the Battle of Fredericksburg, he commands a "Grand Division" of two corps, and is ordered to conduct numerous futile frontal assaults that cause his men to suffer serious losses.

Throughout this period, he conspires against and openly criticizes his army commanders.

Following the defeat at Fredericksburg, he is given command of the Army of the Potomac.

Hooker plans an audacious campaign against Robert E. Lee, but he is defeated by the Confederate Army at the Battle of Chancellorsville.

Hooker suddenly lacks the nerve to marshal the strength of his larger army against Lee, who boldly divides his army and routs a Union corps with a flank attack by Stonewall Jackson.

Hooker begins to pursue Lee at the start of the Gettysburg Campaign, but his poor performance at Chancellorsville prompts Abraham Lincoln to relieve him from command just prior to the Battle of Gettysburg.

He returns to combat in November, leading two corps from the Army of the Potomac to help relieve the besieged Union Army at Chattanooga, Tennessee, and achieving an important victory at the Battle of Lookout Mountain during the Chattanooga Campaign.

He continues in the Western Theater under Maj. Gen. William T. Sherman, but leaves before the end of the Atlanta Campaign when he is bypassed for a promotion to command the Army of the Tennessee.

Hooker becomes known as "Fighting Joe" following a journalist's clerical error reporting from the Battle of Williamsburg; however, the nickname sticks.

His personal reputation is as a hard-drinking ladies' man, and his headquarters is known for parties and gambling, although the historical evidence discounts any heavy drinking by the general himself.

His name is often associated with the slang term for prostitute, although the etymology of that word has been documented to appear in print well before he became a public figure.