In 2005, the General Synod of the United Church of Christ voted to legally recognize and advocate in favor of same-sex marriage and in favor of marriage equality. Each UCC church has local autonomy, so each congregation may adopt or reject this recommendation.

Presbyterian Church USA defines marriage as a union between a man and a woman, a position the General Assembly reaffirmed in 2010. However, in 2000, the church's highest judicial body issued a decision to allow its ministers to bless same-sex unions just so long as the ceremonies were not considered marriage. The church also urged state legislatures to give same-sex couples the right to be joined in civil unions.

United Methodist Church law prohibits clergy from performing same-sex marriages and a minister who takes part in such a ceremony may have ordination revoked.

Although the Episcopal Church has not explicitly established a position in favor of same-sex marriage, in 2006 the church stated its "support of gay and lesbian persons and [opposition to] any state or federal constitutional amendment," prohibiting same-sex marriages or civil unions. Furthermore, in 2009, the church's national convention voted to give bishops the option to bless same-sex unions.

Evangelical Lutheran Church in America defines marriage as "a lifelong covenant of faithfulness between a man and a woman." In August 2009, however, the church adopted a social statement on human sexuality that supports a wide diversity of families, including those of same-gender couples.

Lutheran Church-Missouri Synod takes a different stance on the question. In 2006, the church reaffirmed its position that same-sex marriage is "contrary to the will of the Creator."

Southern Baptist Convention opposes gay marriage and has called on "Southern Baptists not only to stand against same-sex unions but to demonstrate our love for those practicing homosexuality by sharing with them the forgiving and transforming power of the Gospel."

Unitarian Universalist Association of Congregations passed a resolution in support of same-sex marriage in 2005.

There is no universal Buddhist position on same-sex marriage.

The opposes same-sex marriage on the ground that "marriage is a faithful, exclusive and lifelong union between one man and one woman."

Church of Jesus Christ of Latter-day Saints does not endorse same-sex marriage. Its theology stipulates that "marriage between a man and a woman is ordained of God."

The Reform and Reconstructionist Jewish movements support gay and lesbian rights, including same-sex marriage. The Conservative movement, which as a whole does not sanctify gay marriage, allows individual rabbis to choose to recognize same-sex unions. Orthodox Judaism does not accept same-sex marriage.

Islamic law forbids homosexuality, and the practice of homosexuality is a crime in many Islamic countries.

There is no official Hindu position on same-sex marriage. Some Hindus condemn the practice of homosexuality, but others cite ancient Hindu texts, such as the Kama Sutra, that describe homosexual behavior.