American Public University System (APUS) is a private, for-profit, online learning institution that is composed of American Military University (AMU) and American Public University (APU). APUS is wholly owned by American Public Education, Inc., a publicly traded private-sector corporation (NASDAQ: APEI). APUS maintains corporate and academic offices in Charles Town, West Virginia and administrative offices in Manassas, Virginia. APUS offers associate, bachelor's and master's degrees, in addition to dual degrees, certificate programs and learning tracks.

Despite its name, APUS is not a public institution and is not a part of the US government or the US military.

Approximately 56% of APUS’s students reported that they served in the military on active duty at initial enrollment. About 55,000 military service members get tuition assistance (TA) for APUS schools. Another 16,702 use their GI Bill benefits for the schools.

The university was founded in 1991 by Major James P. Etter (USMC, retired) as American Military University. Operations began in January 1993 with the enrollment of 18 graduate students. Initially, the main goal of the university was to meet the unique educational needs of military personnel needing courses in specialized areas, such as counterterrorism and military intelligence, that were not included in typical university course offerings. In the early years, instruction was done through conventional correspondence.

In June 1995 AMU became nationally accredited by the Accrediting Commission of the Distance Education and Training Council (DETC). In January of the following year, the school introduced its first undergraduate programs. In 1998 AMU made the transition from correspondence-based learning to online learning.

In 2002 AMU expanded to become American Public University System and established American Public University, intended primarily for civilians interested in public service programs. In 2006 APUS was granted regional accreditation from the Higher Learning Commission. In 2012 American Public University System resigned its DETC accreditation. The university is listed as tied for 58th place in U.S. News & World Report ranking of online bachelor's degree Programs.

In May 2016, APUS reported a 12% year-over-year decrease in students, down to 98,400 students, and 60,000 alumni worldwide. In July 2016, long-time President Dr. Wallace E. Boston was succeeded as APUS president by former Executive Vice President and Provost Dr. Karan Powell, while continuing his leadership role as CEO of APEI to provide strategic and leadership support to APUS and other APEI ventures. In September 2016, Dr. Vernon Smith was named senior vice president and provost, succeeding Dr. Powell.

APUS is regionally accredited by the Higher Learning Commission. The University's School of Business is accredited by, and several business programs have specialized accreditation from, the Accreditation Council for Business Schools and Programs The University's Bachelor of Science in Nursing (RN to BSN) program is accredited by the Commission on Collegiate Nursing Education. APUS' Master of Public Health program was accredited in July 2017 — retroactive to 22 July 2015 — by the Council on Education for Public Health.

Completion of the Master of Arts in Legal Studies program does not qualify its graduates to sit for the bar examination in any state or province. Prospective MA in Legal Studies candidates are cautioned on this point by APUS itself.

Select APUS programs are also affiliated with and/or recognized by such professional organizations as:

APUS is an open enrollment institution.

The system employs approximately 410 full-time faculty members and 1,800 part-time faculty members. Full-time professors are salaried employees without tenure.

APUS offers 200 degree and certificate programs across six academic schools through American Military University and American Public University, including the following:

According to the National Center for Education Statistics, the overall graduate rate is 46%.

According to the National Center for Education Statistics, APUS' most recent student loan default rate was 20.1%.

American Military University participates in the Servicemembers Opportunity College program, with eligible bachelor's degrees in Homeland Security, Intelligence Studies, Emergency and Disaster Management (Coast Guard only), Criminal Justice, Management, and Business Administration. AMU is also a Navy College Program Distance Learning Partner.

Students at APUS are involved in a variety of different student organizations and honor societies. This includes chapters for the National Association for Environmental Professionals (NAEP), International Association of Emergency Managers (IAEM), Student Veterans of America (SVA), the Society of Human Resources Management, Students for the Exploration and Development of Space (SEDS), and The Saber and Scroll for History students.

Academic Honor Societies include: Alpha Phi Sigma, Sigma Beta Delta, Delta Epsilon Tau, Epsilon Pi Phi, Golden Key, Pi Gamma Mu, Delta Mu Delta, National Society of Collegiate Scholars, and Sigma Iota Rho.

APUS has had a key partnership with Walmart since 2010. Walmart has spent $50 million on the program, chiefly on tuition grants for Walmart workers. According to Walmart, "the potential for educational advancement helps 'further develop a pipeline' for leaders." The program is called Walmart's Lifelong Learning Program. Currently, Walmart workers can get a 15% tuition grant for the online school. College credit may also be given for work experience.