Phineas Taylor Barnum (; July 5, 1810 – April 7, 1891) was an American showman, businessman, and politician, remembered for promoting celebrated hoaxes and founding the Barnum & Bailey Circus (1871–2017) with James Anthony Bailey. He was also an author, publisher, and philanthropist, though he said of himself: "I am a showman by profession ... and all the gilding shall make nothing else of me." According to his critics, his personal aim was "to put money in his own coffers". He is widely credited with coining the adage "There's a sucker born every minute", although no evidence has been collected of him saying this.

Barnum became a small business owner in his early twenties and founded a weekly newspaper before moving to New York City in 1834. He embarked on an entertainment career, first with a variety troupe called "Barnum's Grand Scientific and Musical Theater", and soon after by purchasing Scudder's American Museum which he renamed after himself. He used the museum as a platform to promote hoaxes and human curiosities such as the Fiji mermaid and General Tom Thumb. In 1850, he promoted the American tour of Swedish opera singer Jenny Lind, paying her an unprecedented $1,000 a night for 150 nights. He suffered economic reversals in the 1850s due to bad investments, as well as years of litigation and public humiliation, but he used a lecture tour as a temperance speaker to emerge from debt. His museum added America's first aquarium and expanded the wax-figure department.

Barnum served two terms in the Connecticut legislature in 1865 as a Republican for Fairfield, Connecticut. He spoke before the legislature concerning the ratification of the Thirteenth Amendment to the United States Constitution which abolished slavery and involuntary servitude: "A human soul, 'that God has created and Christ died for,' is not to be trifled with. It may tenant the body of a Chinaman, a Turk, an Arab, or a Hottentot—it is still an immortal spirit". He was elected in 1875 as mayor of Bridgeport, Connecticut where he worked to improve the water supply, bring gas lighting to streets, and enforce liquor and prostitution laws. He was also instrumental in starting Bridgeport Hospital in 1878 and was its first president. Nevertheless, the circus business, begun when he was 60 years old, was the source of much of his enduring fame. He established "P. T. Barnum's Grand Traveling Museum, Menagerie, Caravan & Hippodrome" in 1870, a traveling circus, menagerie, and museum of "freaks" which adopted many names over the years.

Barnum was married to Charity Hallett from 1829 until her death in 1873, and they had four children. In 1874, a few months after his wife's death, he married Nancy Fish, his friend's daughter who was 40 years younger than P. T. Barnum. They were married until 1891 when Barnum died of a stroke at his home. He was buried in Mountain Grove Cemetery, Bridgeport, which he designed himself.