The United Church of Christ (UCC) is a mainline Protestant Christian denomination primarily in the Reformed tradition but also historically influenced by Lutheranism. The Evangelical and Reformed Church and the Congregational Christian Churches united in 1957 to form the UCC. These two denominations, which were themselves the result of earlier unions, had their roots in Congregational, Evangelical, and Reformed denominations. The UCC's 5,287 congregations claim 1,080,199 members, primarily in the United States.

The UCC maintains full communion with other mainline Protestant denominations, while many congregations choose to practice open communion. The denomination places high emphasis on participation in worldwide interfaith and ecumenical efforts. The national settings of the UCC have historically favored liberal views on social issues, such as civil rights, gay rights, women's rights and abortion rights. However, United Church of Christ congregations are independent in matters of doctrine and ministry and may not necessarily support the national body's theological or moral stances. It is self-described as "an extremely pluralistic and diverse denomination".

The term Church of Christ may refer to:

United and uniting churches are churches formed from the merger or other form of union of two or more different Protestant denominations.

Perhaps the oldest example of a united church is found in Germany, where the Evangelical Church in Germany is a federation of Lutheran, United and Reformed churches, a union dating back to 1817 in some parts of Germany (see Prussian Union). The first union was at a synod in Idstein to form the Protestant Church in Nassau in August 1817, commemorated in naming the church of Idstein Unionskirche 100 years later.

Around the world, each united or uniting church comprises a different mix of predecessor denominations. Trends are visible, however, as most united and uniting churches have one or more predecessors with heritage in the Reformed tradition (either Presbyterian, Congregationalist, or both) and many are members of the World Alliance of Reformed Churches.

In the 1950s and 1960s an ecumenical spirit emerged in many churches in the United States of America, leading to a conciliar movement known in some circles as Conciliarity. A product of this movement was the Consultation on Church Union (COCU). COCU disbanded formally in 2002 but moved into the Churches Uniting in Christ movement.

Jeremiah Alvesta Wright, Jr., (born September 22, 1941) is Pastor Emeritus of Trinity United Church of Christ (TUCC), in Chicago with a congregation exceeding 6,000. In early 2008, Wright retired after 36 years as the Senior Pastor and no longer has daily responsibilities at the church.

Following retirement, Wright's beliefs and preaching were scrutinized when segments of his sermons were publicized in connection with the presidential campaign of Barack Obama, including his contention that the [[attacks of September 11, 2001, were proof that "America's chickens are coming home to roost" and such statements as "...not God Bless America. God damn America." Obama responded to the Wright controversy in a speech entitled "A More Perfect Union."

On April 27, 2008, Wright defended his record in a speech before the National Association for the Advancement of Colored People (NAACP), saying he was not "divisive" but "descriptive" and that the black church experience, like black culture, was "different" but not "deficient".