Patrick Ryan (15 March 1853 – 14 December 1900) was an Irish American boxer, and became the bare-knuckle American heavyweight champion on 30 May 1880, after he won the title from Joe Goss. He retained the title until losing it to the exceptional John L. Sullivan on 7 February 1882.

Ryan fought only ten major bouts, but as many as twenty-five exhibitions including many against Sullivan in his late career. Exhibitions brought him income, but with fewer rounds and less risk. As a stout youth, Ryan worked on the construction of the Erie Canal before pursuing his boxing career. After opening a Troy saloon in 1874, he caught the attention of the athletic director of Rensselaer Polytechnic Institute, Jim Killoran. Killoran saw Ryan dealing with troublemakers and drunks at the saloon and decided to train him as a prizefighter.

In the most significant win of his career, Ryan defeated bare-knuckle heavyweight championship Joe Goss on 30 May 1880, in Collier's Station, West Virginia. In the 87th round, Goss was unable to continue and the contest was stopped after 90 minutes. Ryan's final blow was a right that knocked out Goss. Up until that time, the fight was tight and well-contested. Goss's seconds claimed a foul in the 87th, and with him being unable to continue, the judges awarded the bout to Ryan. His opponent appeared winded, but Ryan was terribly battered around the face and body. Ryan was nearly twenty pounds heavier and nearly six inches taller than Goss, a discrepancy which would have never been allowed in today's boxing, and may have made the difference in the match.

Exhibitions, 1881

In 1881, Ryan fought eight exhibition bouts primarily in the New York area, in which he fought Goss again on 18 May, and then fought John Dwyer on 2 July. He later faced Captain James Dalton on 1 October, a well-known regional opponent. Sullivan, the proud Irishman, wore green pants and stockings, to Ryan's white pants and stockings with spiked boxing shoes. The fight was to be a bare-knuckle contest governed by the London Prize Ring Rules, and fought on dirt in a 24-foot ring. The championship contest may well have been Sullivan's first bare-knuckle bout. Each side put up $2,500 with an additional $1,000 put up for each side. Richard K. Fox, owner of the boxing magazine Police Gazette, was the backer for Ryan. James Keenan, of Boston, was the backer for Sullivan. This made the winner's stake $3,500, one of the larger American purses to date. There were about 2,000 spectators present.

Following an old tradition, Sullivan threw his hat in the ring at 11:45 am. Ryan came into the ring at 11:57 with the crowd estimated at 5,000. The men then approached the scratch line in the center of the ring and shook hands. Sullivan's fame and his acceptance among both American aristocracy and the lower classes was unique and new in the boxing world, and would help both boxers draw large crowds to the exhibitions they would later stage in the Northeast.

In Ryan's era, boxing titles were informal, as there were no globally recognized sanctioning bodies to bestow legitimacy to a world title. Some sources refer to him as the "Heavyweight Champion of America" while others call him a world champion. To a large extent, he was recognized as the world champion of boxing while he held the title, as heavyweights held reign over other weight classes at the time, and had larger followings.

Meeting fewer boxing opponents, 1883-1886

Ryan was less active in boxing in 1883 when he knocked out Montana champion Jack Waite in a three-round exhibition on 21 October. The results of several fights he scheduled that year failed to appear in the press. He continued to meet few opponents in 1884–1885, though on 19 January 1885, Ryan fought a no contest bout with Sullivan at New York's Madison Square Garden. Some sources report Ryan lost, but in any event, police intervened in the first round and stopped the fight.

Ryan fought a two-round draw with Frank Glover on 13 September 1886, in Chicago. Ryan fought at 210, above his normal fighting weight and was described as too "fleshy" by a Wisconsin paper. The referees split on a decision, so a draw was called, when a dozen police officers intervened and stopped the fight in the second round. The bout was fought on a boat in the rain using the London Prize Rules and close to 1,500 spectators had huddled nearby to see the match. The fight was fought with gloves and adhered to the Marquess of Queensberry Rules, first published in 1867.

Ryan lost to Joe McAuliffe, who knocked him out in three rounds on 23 December 1887, in San Francisco. The fight was fought with gloves using the new Queensberry Rules, which necessitated their use. McCauliffe had a thirteen-year age advantage, and was known as a powerful man and a strong puncher.

Ryan was arrested on a charge of grand larceny of $100 on 21 21 February 1888, in San Francisco, where he was still living at the time, though once the charge was found to be fraudulent, he was quickly acquitted and released.

Several newspapers reported that Ryan lost to John Donner on 4 May 1888, in Duluth, Minnesota, by knockout, though a reliable source reported the boxer was not Paddy Ryan the ex-champion and that Ryan was living in San Francisco.

Ryan performed in a series of lucrative and well-attended exhibitions with Sullivan, primarily in New England, from 1891 to 1897, before retiring from boxing.

On 5 March 1899, Ryan refereed the Alt Allen vs. Fred Wyatt match in Plattsburgh, New York. Ryan died from his disease on 14 December 1900 in Green Island, New York, aged 49. He was buried in St. Mary's Cemetery. He was survived by a daughter.

Ryan was elected to The Ring magazine's Hall of Fame in 1973.