In the beginning Portland Baptist Bible Institute was organized through the work of Walter B. Hinson in 1925. Next year, efforts were begun to establish a graduate-level seminary to provide a theological education of greater depth in the Northwestern United States. And later in 1927 the Western Baptist Theological Seminary was officially dedicated.

By 1944 Western Seminary has opened several extension campus locations in the Western United States to support residential studies in other major cities. The first campus was founded in San Jose, CA in 1986. Another was founded in 1988 Phoenix, AZ. And later in 1991 was opened campus in Sacramento, CA and in Seattle, WA, in 1992. Since this time, the Phoenix and Seattle campuses have become independent seminaries.

Western Seminary has developed many solutions to help non-residential students complete their coursework. In 1981, Western began a distance learning program that served hundreds of students per year in study centers across America and overseas through interactive video curriculum. Western Seminary, through the Center for Lifelong Learning, is approved by the Association of Theological Schools to deliver up to one half of a two-year Master of Arts degree program, and up to two-thirds of a three-year Master of Divinity degree program, by distance education. Moreover, Western Seminary offers programs which may be earned entirely online through distance education. Individuals can earn Graduate Studies Diploma and Certificate entirely through distance education. In addition Master of Arts in Counseling and Marriage and Family Therapy programs may be earned online too.

Western Seminary is accredited to award master's and doctor's degrees by the Northwest Commission on Colleges and Universities (NWCCU) and is an accredited member of the Association of Theological School (ATS).