John Joseph Cardinal O'Connor, (January 15, 1920 – May 3, 2000) was the eleventh bishop (eighth archbishop) of the Roman Catholic Archdiocese of New York, serving from 1984 until his death in 2000.

He was born in Philadelphia, Pennsylvania to a family of Irish descent, and ordained a priest on December 15, 1945. He was initially assigned to St. James High School in Chester, Pennsylvania. He obtained a master's degree in advanced ethics from Villanova University and a doctorate in political science at Georgetown University in 1970 where he wrote his dissertation under future United Nations Ambassador Jeanne Kirkpatrick and took classes at the Edmund A. Walsh School of Foreign Service. During his career he also performed the rite of exorcism.

He joined the United States Navy in 1952 as a Korean War chaplain, often entering combat zones in order to perform mass and administer last rites to soldiers. He rose through the ranks to become rear admiral and chief of Navy chaplains. He was appointed Auxiliary Bishop of the Archdiocese for the Military Services by Pope John Paul II on April 24, 1979 and ordained a bishop on May 27, 1979 with the titular see of Curzola. He was appointed Bishop of Scranton, Pennsylvania on May 6, 1983 and installed in that position June 29, 1983. He was appointed Archbishop of New York, New York on January 26, 1984 and installed in that position on March 19, 1984. He was elevated to Cardinal on May 25, 1985. He never participated in a conclave.

As Archbishop of New York, O'Connor was a complex figure in a very visible position. He proved very media-savvy in the media-centric city, yet he could be a stern critic of New York's political leaders when he deemed it necessary.

He skillfully brought to bear the power and prestige of his office to bear witness to traditional Catholic doctrine in a world frequently hostile to it. He was an outspoken critic of abortion, the death penalty, gay rights, and violence, including war, regularly questioning the unchecked military spending of the 1980s. As a supporter of the rights of the worker he was known as a close friend of the labor movement and trade unions, thus earning the sobriquet: "The Patron Saint of the Working Man."

As head of the largest and arguably most visible Catholic diocese in the United States, he was also a very prominent public figure. He was a friend of President Ronald Reagan and sometimes served as an advisor to him on matters of ethics and morality.

O'Connor was active in interfaith and ecumenical relations. The Jewish Council for Public Affairs called him, "a true friend and champion of Catholic-Jewish relations, but as a humanitarian who used the power of his pulpit to advocate for disadvantaged people throughout the world and in his own community." He strongly denounced anti-Semitism, and wrote a moving apology to Jewish leaders in New York for past harm done to the Jewish community.

Cardinal O'Connor was, per Catholic teaching, opposed to homosexual acts, but additionally opposed civil rights legislation for gays. He was constantly at odds with much of the gay community in New York City throughout his sixteen year tenure as Archbishop. He opposed every gay-related bill considered on the city and state level, and condemned proposed legislation backed by Mayor Rudolph Giuliani that would grant homosexuals, lesbians, and unmarried couples the right not to be discriminated against in housing, public accommodations, employment, and rent-related affairs. He also strongly opposed Mayor Ed Koch's executive order requiring all social service agencies, including those run by the Church, to provide equal services to homosexuals. The Cardinal refused on the grounds that it would make the Church appear to be sanctioning homosexual practices and lifestyle. He also prohibited a pro-homosexual group from meeting in New York parishes, and supported efforts by the Ancient Order of Hibernians to prevent groups representing gay Irish people from marching under that banner in New York's St. Patrick's Day parade. It should be noted however, that he did celebrate Mass with Father John Harvey's Courage, a ministry to homosexual men and women who seek to live by the Church's teachings on human sexuality.

The Cardinal opposed condom distribution as an AIDS-prevention measure, viewing it as being contrary to the Church's teaching that contraception is a sin. Some have criticized this position on the grounds that condoms distributed to gay men are not contraceptives, since gay men cannot conceive. O'Connor's response was that using an "evil act" was not justified by good intentions, and that the Church should not be seen as encouraging its members to perform sinful acts, regardless of the situation. (This latter response, it should be noted, is consistent with the Church's teachings on the sin of scandal, but still logically flawed in labelling use of a condom by gays as "contraception".) He also agreed with the Church's position that the only sure way to prevent infection is sexual abstinence, as condoms at the time were shown to be only 90% effective against HIV transmission. HIV activist group ACT-UP was appalled by the Cardinal's apparent opinion that it was sinful for an HIV positive person to use a condom to prevent transmission of HIV to his HIV negative partner, an opinion they believe would translate directly into more deaths. This caused many of the confrontations between the group and the Cardinal.

Cardinal O' Connor was however very supportive of those who were infected with AIDS and HIV. Early on in the AIDS epidemic, he approved the opening of a specialized AIDS unit to provide medical care for the sick and dying in St. Clare's Hospital in Manhattan, the first of its kind in the state. He often nurtured and ministered to dying AIDS patients, many of whom were homosexual. Even though he frequently condemned homosexuals (many of whom had invaded St. Patrick's Cathedral to angrily interrupt services), he would not allow his moral differences to interfere with ministering to them. As USA Today reported, he "washed the hair and emptied bedpans of dying AIDS patients, some too sick to know who he was." Former New York Governor Mario Cuomo once said "No place in the country are they working more aggressively to help AIDS patients than in the archdiocese." O'Connor was one of the members of President Ronald Reagan's 1987 presidential commission on AIDS, serving alongside 12 other members with no expertise on the subject, including Richard DeVos and Penny Pullen. The commission was considered an embarrassment by medical authorities, and a fiasco by members of the Reagan Administration, even though recommendations to Congress were eventually made.

A staunch foe of abortion (he was characterized by Jerry Falwell as "a pro-life hero"), O'Connor also testified in favor of New York state legislation which sought to make human cloning research a crime punished by up to seven years of prison, presenting what the Daily News called "an apocalyptic vision" of clones as drones or slaves. The legislation was ultimately withdrawn.

Because of a rise in the number of people who were looking for help from demonic attack in 1992 the Cardinal appointed Father James J. LeBar as chief exorcist of the archdiocese of New York and three other priests as exorcists, a rare occurrence in modern times.

When he reached the bishops' retirement age of 75 in January 1995, he submitted his resignation to the pope as required, but the pope did not accept it.

In 1999 O'Connor was diagnosed as having a brain tumor, to which he eventually succumbed.

He died in the Archbishop's residence, and is interred in the crypt under the altar of St. Patrick's Cathedral.

UN Secretary General Kofi Annan, President Bill Clinton and his wife, Vice President Al Gore, Former President George H.W. Bush, then Texas Governor George W. Bush, New York Governor George Pataki, and then New York City mayor Rudolph Giuliani were among the dignitaries who attended his funeral in St. Patrick's Cathedral in NYC.

Cardinal O'Connor was posthumously awarded the Jackie Robinson Empire State Medal of Freedom by the Governor of New York, George Pataki on December 21, 2000. On March 7, 2000 O'Connor was awarded the Congressional Gold Medal by unanimous support in the United States Senate and only one vote against the resolution in the United States House of Representatives. Congressman Ron Paul, a libertarian Republican from Texas, opposed on the grounds that awarding the medal was not among the powers of Congress listed in the Constitution.

O'Connor's tenure earned him the enmity of New York's gay community, which had become radicalized in the late 80s and early 90s. O'Connor was a favorite object of scorn and ridicule in ACT-UP's demonstrations. Michael Petrelis, a founding member of ACT UP, indicated that the group "came to St. Patrick's in 1989 to repel the church's destructive intrusion into public policies concerning AIDS, gay civil rights and women's reproductive rights." The strong feelings that Cardinal O'Connor's campaigning against gay civil rights inspired were evoked at his passing, when Time Out New York, a weekly city entertainment guide, described his death as one of the best things to happen to the gay community in 2000, saying "The press eulogized him as a saint, when in fact, the pious creep was a stuck-in-the-1950s anti-gay menace. Good riddance!". The resulting cries of outrage forced the magazine to apologize. Brendan Fay, of the Catholic gay group DignityUSA, summarized that "O'Connor will certainly not be remembered as a friend or advocate at our time of greatest need." This, even though beginning in 1995, O'Connor held a dialogue with the group twice a year. Jeff Stone, a spokesman for Dignity, did note, "We are saddened by his death."

With O'Connor's death the controversy surrounding his high-profile and vocal advocacy of the traditional and orthodox views of the Catholic Church has left him with a mixed legacy. Lauded by some traditionalists, considered a demon by many in the gay community, he was without a doubt one of the most controversial American clerics of the late 20th century.

• List of Roman Catholic Bishops and Archbishops of New York
• List of notable cardinals

• Catholic New York stories on Cardinal O'Connor
• Anna Quindlen, criticising Cardinal O'Connor in the "Public and Private" column of the New York Times 17 February 1993
• President George W. Bush, speaking in St. Patrick's Cathedral, New York when he gave the Congressional Gold Medal to the late Cardinal's family & the new Archbishop 10 July 2001
• Cardinal O'Connor's publicly expressed opinions, quoted from his personal archives