The city of Rexburg is located in Madison County, Idaho, in the United States. At the time of the census in 2020, the population was 39,409. The city is the biggest city in Madison County and also serves as the county seat. The Rexburg, Idaho Micropolitan Statistical Area consists of Fremont County and Madison County in addition to the city of Rexburg as its primary city. In this city is located Brigham Young University-Idaho, often known as BYU-Idaho. This university is a private college that is run by The Church of Jesus Christ of Latter-day Saints (LDS Church).