Rexburg is a city located in Madison County, Idaho, in the United States. It serves as the county seat and is the largest city within Madison County. According to the 2020 census, the city had a population of 39,409 residents.
The city functions as the principal city of the Rexburg micropolitan area, which encompasses both Fremont and Madison counties. It is notably home to Brigham Young University–Idaho (BYU-Idaho), a private educational institution operated by the Church of Jesus Christ of Latter-day Saints.