Open communion, also known as open table, eucharistic hospitality, or eucharistic sharing, is a practice of some Christian Churches of allowing both members of their denomination, as well as non-members, to receive the Eucharist. Most churches that practice open communion require that the communicant be a baptized believer, and other requirements may apply as well. Christian denominations that practice open communion include Old Catholics, Moravians, Anglicans, Methodists, Community of Christ, and Pentecostals, as well as certain Lutherans, Reformed Christians (including some in the Presbyterian, Congregationalist, and Continental Reformed churches), Baptists and Plymouth Brethren. Those Christian denominations that practice open communion hold that the Eucharist is Christ’s Supper and therefore, all are welcome to commune.

Open communion is the opposite of closed communion, in which the sacrament is reserved for members of the particular church or others with which it is in a relationship of full communion or fellowship, or has otherwise recognized for that purpose. Closed communion may refer to either a particular denomination or an individual congregation serving Communion only to its own members.

Generally, churches that offer open communion to other Christians do not require an explicit affirmation of Christianity from the communicant before distributing the elements; the act of receiving is an implicit affirmation. Some churches make an announcement before communion begins such as "We invite all who have professed a faith in Christ to join us at the table."

Open communion is generally practiced in churches where the elements are passed through the congregation (also called self-communication). However, it is also practiced in some churches that have a communion procession, where the congregation comes forward to receive communion in front of the altar; such is the case in the United Methodist Church, the Episcopal Church, most Anglican churches, and some Lutheran churches.

Those practising open communion generally believe that the invitation to receive communion is an invitation to Christ's table, and that it is not the province of human beings to interfere between an individual and Christ. Some traditions maintain that there are certain circumstances under which individuals should not present themselves for (and should voluntarily refrain from receiving) communion. However, if those individuals were to present themselves for communion, they would not be denied. In other traditions, the concept of being "unfit to receive" is unknown, and the actual refusal to distribute the elements to an individual would be considered scandalous.

The Old Catholic Church practices open communion.

Some Independent Catholic Churches, such as the American Catholic Church in the United States, American National Catholic Church, and Brazilian Catholic Apostolic Church practice open communion.

All bodies in the Liberal Catholic Movement practise open communion as a matter of policy.