A megachurch is a church having 2,000 or more in average weekend attendance. The Hartford Institute's database lists more than 1,300 such Protestant churches in the United States. According to that data, approximately 50 churches on the list have attendance ranging from 10,000 to 47,000. While 3,000 individual Catholic parishes (churches) have 2,000 or more attendants for an average Sunday Mass, these churches are not seen as part of the megachurch movement.

Globally, these large congregations are a significant development in Protestant Christianity. While generally associated with the United States, the phenomenon has spread worldwide. In 2007, five of the ten largest Protestant churches were in South Korea. The largest mega church in EE.UU is Lakewood Church in Houston, Texas with more than 40.000 members every weekend and the current largest megachurch in the world is South Korea's Yoido Full Gospel Church, with more than 830,000 members as of 2007.

The origins of the megachurch movement, with a large number of local congregants who return on a weekly basis can be traced to the 1950s. There were large churches earlier in history, but they were considerably rarer. Examples include Charles Spurgeon's Baptist Metropolitan Tabernacle in London which attracted 5,000 weekly for years in the late 19th century, and religious broadcaster Aimee Semple McPherson's Angelus Temple in Los Angeles, which was similarly large. The advent of television in the 1950s, and the Internet in the 1990s and 2000s have been seen as a motivator for megachurches as megachurch services are often broadcast.^{[citation needed]}

Eddie Lee Long (born May 12, 1953) is the senior pastor of New Birth Missionary Baptist Church, a megachurch in unincorporated DeKalb County, Georgia, United States, near Lithonia. When Long started as pastor for New Birth Church in 1987, there were 300 church members. Since his installation, membership has grown to 25,000.

During this time, Long was the focus of Senate investigations concerning whether he has personally profited from his church's tax exempt status and lawsuits alleging sexual relations with underage male members of his parish. Long has denied wrongdoing through his attorneys and has settled the lawsuits out of court.

Eddie Long attended North Carolina Central University in Durham, North Carolina where he received a Bachelor's degree in Business Administration in 1977.

Long donated $1 million to North Carolina Central University in 2008 to establish a professorship in his honor. Long said, "I am making (the donation) from my own personal income," which comes from various real estate ventures and also as royalties from his books.

Ted Arthur Haggard (born June 27, 1956) is an American evangelical pastor. Known as Pastor Ted to the congregation he served, he was the founder and former pastor of the New Life Church in Colorado Springs, Colorado; a founder of the Association of Life-Giving Churches; and was leader of the National Association of Evangelicals (NAE) from 2003 until November 2006.

In November 2006, escort and masseur Mike Jones alleged that Haggard had paid him for sex for three years and had also purchased and used crystal methamphetamine. A few days later Haggard resigned from all of his leadership positions.

After the scandal was publicized, Haggard entered three weeks of intensive counseling, overseen by four ministers. In February 2007, one of those ministers, Tim Ralph, said that Haggard "is completely heterosexual." Ralph later said he meant that therapy "gave Ted the tools to help to embrace his heterosexual side." On June 1, 2010 Haggard announced that he intended to start a new church in Colorado Springs. In the February 2011 issue of GQ, Haggard said "...probably, if I were 21 in this society, I would identify myself as a bisexual."

Marcus Lamb (born October 7, 1957) is an American televangelist, minister and Christian broadcaster. He is most well known as the co-founder, president, and CEO of the Daystar Television Network, the second-largest Christian television network in the world. The network has 90 TV stations and satellite and cable coverage that reaches 100 million U.S. households and more than 200 countries. The estimated value of the network is $230 million.

Marcus was born October 7, 1957 in Macon, Georgia. He grew up in a Christian home, attending the East Macon Church of God with his family. He became a Christian at the age of five and continued in church attendance and work as he grew older. He began to preach as an evangelist at age fifteen. He graduated from high school at a young age and was enrolled at Cleveland, Tennessee’s Lee University at age sixteen. Three years later he graduated with Magna Cum Laude honors. In 1982, four years after finishing college, he married Joni Trammel of Greenville, South Carolina. The couple spent their early years of marriage as traveling evangelists. Marcus was ordained as a Bishop with the Church of God and they visited churches throughout the Southeast to teach the gospel.

Joel Scott Osteen (born March 5, 1963) is an American author, televangelist, and the senior pastor of Lakewood Church in Houston, Texas. His ministry reaches over seven million broadcast media viewers weekly in over 100 nations around the world.

Born in Houston, Texas, Osteen is one of five children of John Osteen and Dolores ("Dodie") Pilgrim. His father, a former Southern Baptist pastor, founded Lakewood Church where Osteen is the current senior pastor. Osteen married his wife, Victoria L. Iloff, on April 4, 1987. They have two children, Jonathan and Alexandra. His older siblings, Paul, Lisa, and Tamara, and his younger sister, April, are also involved in full-time ministry. His half-brother Justin does missionary work out of New York.

After 17 years producing the church's television program, Osteen succeeded his father on October 3, 1999, as pastor of Lakewood Church. He had only preached once in his life, the week before his father's death. Today, Lakewood Church services, led by Pastor Joel Osteen, are seen in over 100 nations around the world. Joel Osteen's first book, Your Best Life Now: 7 Steps to Living at Your Full Potential, was released in October 2004. In December 2006, he was named one of the year's "Ten Most Fascinating People" by Barbara Walters. Former presidential candidate John McCain has described Osteen as "inspirational".