John Andrew Hostetler was born to an Old Order Amish family in the Kishacoquillas Valley (known locally as the Big Valley) region of Mifflin County, Pennsylvania, USA on October 29, 1918. He was the fifth of seven children of Joseph and Nancy (Hostetler) Hostetler. At the age of eleven, his parents moved to Iowa. As a youth he supervised his father's turkey operation, took courses on poultry raising, and received a poultry judging license from the American Poultry Association. He discovered that he enjoyed reading more than raising turkeys and feeding hogs. He was sixteen when his essay "Some Effects of Alcohol and Tobacco" was published by the Mennonite youth paper The Words of Cheer. Never baptized in the Amish church, in 1935 Hostetler joined the Mennonite Church. He attended Hesston College in 1941, but was soon drafted and served with Civilian Public Service in several locations. He graduated from Goshen College in 1949 with a degree in sociology. While at Goshen he assisted dean Harold S. Bender by writing articles on the Amish and similar groups for the four-volume Mennonite Encyclopedia which Bender was editing, beginning a productive and prolific academic career.

He married Hazel Schrock in June 1949. The Hostetlers then moved to State College, Pennsylvania where John began graduate studies in rural sociology at the Pennsylvania State University. In 1951, his wife and a daughter died in childbirth, the same year that Hostetler's Annotated Bibliography on the Amish won the University of Chicago's annual Folklore Prize. In 1953 Hostetler married Beulah Stauffer Hostetler, a book editor at Herald Press. They had three daughters together, and their marriage marked the beginning of a 48-year collaboration on many projects. He died on August 8, 2001 at the age of 82.

Dismayed by inaccurate popular essays on the Amish, Hostetler published Amish Life (Herald Press, 1952) and The Amish (Herald Press, 1995), books still in print at his death, whose combined sales approached 850,000 copies at that time. He received his Ph.D. from the Pennsylvania State University in 1953 for a dissertation entitled The Sociology of Mennonite Evangelism which was subsequently published by Herald Press. During a five year stint at the Mennonite Publishing House, he served as book editor and also wrote a history of the press, God Uses Ink (1958).

Beginning in 1959 he held faculty teaching appointments at the University of Alberta, Penn State Abington (Penn State Ogontz campus), and Temple University where he retired in 1985. He lectured widely at colleges and universities and held several visiting professorships including five years (1986-1990) as a Distinguished Scholar-in-Residence at the Young Center for Anabaptist and Pietist Studies at Elizabethtown College where his wife also held a teaching appointment.

Hostetler's scholarship and publications included at least twenty articles in church periodicals, nearly that number in the Mennonite Quarterly Review and the Mennonite Historical Bulletin as well as some twenty additional articles in other scholarly journals including the Journal of the Royal Anthropological Institute and the American Journal of Medical Genetics. He contributed at least 15 chapters to edited books as well as several essays to encyclopedias. Hostetler produced eight full length books and six booklets for popular audiences including the best selling Amish Life. His most important and influential book was Amish Society (Johns Hopkins); first published in 1963, with a fourth edition in 1993, it became one of the best selling volumes in the history of the Johns Hopkins University Press. Hutterite Society (Johns Hopkins, 1974) provided an authoritative account of Hutterite life and society. Other major books included Children in Amish Society (Holt, Rinehart & Winston, 1971) coauthored with his long-time colleague Gertrude Enders Huntington, and Amish Roots (Johns Hopkins, 1989). At the Amish Tricentennial Conference at Elizabethtown College in 1993, Hostetler was recognized by friends and colleagues and presented with a festschrift, The Amish and the State (Johns Hopkins, 1993) which honored his scholarly contributions.

During the early 1960's Hostetler organized an extensive study of Hutterite religious, educational and social practices, with particular focus on socialization patterns, in three colonies, two in southern Canada and one in the northern US state of Montana. The study was funded by the US Office of Education and enlisted numerous consultants and fieldworkers, the latter headed by anthropologist Gertrude Huntington who lived with some of her family as participating members of an Alberta colony for 7 weeks one summer. Hostetler and Huntington published the findings of their study in The Hutterites in North America in 1967...it has been reprinted in several new editions since then.

In addition to his formal publications Hostetler wrote many research reports, directed six funded research projects, and served as an expert witness in at least five court cases involving minority groups, the most prominent one being Wisconsin v. Yoder which was heard by the U.S. Supreme Court in 1972. He was an active participant in the National Committee for Amish Religious Freedom. Hostetler served as an advisor to two major films: The Amish: A People of Preservation (1976) and The Hutterites: To Care and Not to Care (1983). Among numerous awards, John A. Hostetler was a Fulbright Scholar, received an honorary doctorate from Elizabethtown College, and was recognized by the Society for German-American Studies and the National Historic Communal Societies Association.

Through publication and contact with the public media Hostetler served as the leading national interpreter of Amish and Hutterite communities throughout the last half of the twentieth century. As a champion of religious liberty, he was instrumental in preserving and protecting fundamental religious rights of religious minorities, working in quiet and sensitive ways to build bridges of understanding and respect between Old Order communities and the larger world. One of his most enduring accomplishments was his ability to nurture and maintain the trust of leaders and members of Old Order communities.