Nelson University, formerly Southwestern Assemblies of God University (SAGU), is a private Christian university in Waxahachie, Texas. Nelson is accredited by the Southern Association of Colleges and Schools Commission on Colleges and endorsed by the Assemblies of God USA. The university offers associate, bachelor's, master's, and doctoral degrees in a variety of liberal arts programs, as well as programs in Bible and church ministries.

On August 1, 2024, Southwestern Assemblies of God University changed its name to Nelson University.

Nelson University began life as three separate Bible schools. The first, known as Southwestern Bible School, was established in 1927 in Enid, Oklahoma, under the leadership of the Reverend P.C. Nelson. The second, Shield of Faith Bible Institute, was founded in Amarillo, Texas, in 1931 under the direction of the Reverend Guy Shields. It included not only a Bible school, but also a grade school and a high school. The third, which was operated as Southern Bible College in connection with the Richey Evangelistic Temple, began in 1931 at Goose Creek, Texas (now Baytown), in 1931. It was started by Reverend J. T. Little in Trinity Tabernacle and moved to Houston in 1933. The school's name was then changed to Southern Bible Institute.

The Bible school division of Shield of Faith Bible Institute was moved to Fort Worth in 1935. The high school division was transferred the following year. In 1940, a merger resulted in Southern Bible Institute, moving to Fort Worth. The combined school, operating as South Central Bible Institute, came under the ownership and direction of the Texas District Council of the Assemblies of God.

The school in Enid merged with South Central in 1941, at which time the name was changed to Southwestern Bible Institute. In 1943, the institute was moved to its present facilities in Waxahachie, Texas. During the 1944–45 term, a junior college curriculum was added to the school's program. The Junior College Division soon accounted for about half of the enrollment in the college.

Southwestern Bible Institute became a regional school in 1954. At that time seven districts of the Assemblies of God—Arkansas, Louisiana, New Mexico, North Texas, Oklahoma, South Texas and West Texas—owned and operated the school. In 1969, the Rocky Mountain District, composed of Colorado and Utah, was admitted to the Region. The Mississippi District was then added to the Region in 1979. In 1980, the Rocky Mountain District voted to withdraw from the Southwestern Region and to remain neutral.

The proposal to change the name of Southwestern was ratified by all seven districts, and the name became Southwestern Assemblies of God College. In 1963, the upper two years of the college were renamed Southwestern College of the Bible. In 1968, the separation of the divisions of the college was made more complete, and the Junior College was designated Southwestern Junior College of the Assemblies of God. In 1988 the two divisions were reunited.

Beginning in the early nineties, Southwestern experienced phenomenal enrollment increases. From 596 students in the fall of 1991, enrollment grew to 1492 students in 1997. Along with the enrollment increase, opportunities to expand the curriculum and programs developed. In December 1994, the Board of Regents unanimously approved the name change to Southwestern Assemblies of God University to more accurately reflect its purpose and mission as a Bible university of theological and professional studies.

In 1996, Nelson University expanded to include a graduate school. Approximately nineteen graduate programs are available through Nelson University's Harrison School of Graduate Studies.

In 2015, Nelson University was granted an exception to Title IX, allowing it to discriminate against LGBT students for religious reasons. In 2016, the organization Campus Pride ranked the college among the worst schools in Texas for LGBT students. Nelson University responded to the negative ranking by saying that the anti-LGBT student policy is clearly articulated to prospective students before they attend.

The university's handbook lists homosexuality as an offense for which a student can be expelled. In 2008 3 members of LGBT rights group Soulforce were arrested for trying to start a protest on campus.

In 2004, the academic divisions of the university realigned into two colleges, the College of Bible & Church Ministries and the College of Arts & Professions. Both colleges maintain Bible-based curriculum and strive to fulfill the mission of Nelson University.

Since 2000, Nelson University has added 24 new academic programs, bringing the total to more than 60 programs. Additionally, under the direction of President Kermit Bridges, the campus has continued to grow. In 2006–2007, Teeter and Bridges Halls were added. They were followed by the new Alton Garrison Student Wellness Center in 2009.

Amidst the physical expansion, Nelson University experienced consecutive record enrollments in Fall 2007, Fall 2008, Fall 2009, and Fall 2010 reaching a milestone of 2,064.

Nelson University is accredited by the Southern Association of Colleges and Schools Commission on Colleges (SACSCOC) to award associate, baccalaureate, masters, and doctorate degrees. Southwestern's Teacher Education Program is approved by the Texas Education Agency.

The Nelson athletic teams are called the Lions. The university is a member of the National Association of Intercollegiate Athletics (NAIA), primarily competing in the Sooner Athletic Conference (SAC) since the 2013–14 academic year. They are also a member of the National Christian College Athletic Association (NCCAA), primarily competing as an independent in the Central Region of the Division I level. The Lions previously competed in the Red River Athletic Conference (RRAC) from 1998–99 to 2012–13.

Nelson University competes in 14 intercollegiate varsity sports: Men's sports include baseball, basketball, cross country, eSports, football, soccer and track & field; while women's sports include basketball, cross country, eSports, soccer, softball, track & field and volleyball. There is a cheerleading squad. The school colors are purple and gold.

Nelson University holds their football home games at Lumpkins Stadium. All other home games are played on campus.

The 2012–13 school year made 2013 a record-setting year for Nelson Lions Basketball, with the Lions achieving the NAIA second-place championship ranking.

Influenced by Vice President George Brazell's acquisition of a four-month-old lion cub named Judah, Southwestern adopted the "Lion of Judah" as its mascot in 1963.

• Gary Elkins (BS '78), former Republican member of the Texas House of Representatives from his native Houston, Texas
• Mike Evans, author, journalist, Middle East commentator.
• Marla Hanson, screenwriter and ex-model
• Jerry Lee Lewis, expelled for having played a boogie-woogie rendition of "My God Is Real".
• Marlin Maddoux, conservative Christian radio host and founder of Point of View Ministries.
• Mike Murdock, televangelist and contemporary Christian singer-songwriter. Left in 1966 after three semesters.

• Official website
• Official athletics website