The Union is the busiest building on campus, housing the admissions office, book shop, career center, student art gallery, cafeteria, the Oneota Market coffee and sandwich shop, and Marty's, a special place for food and entertainment.
The Union is also home to the president’s and dean’s offices and the Diversity Center, along with the student life and student activities offices.
KWLC, the college's student radio station, and CHIPS, the student newspaper, are both headquartered in the Union.
The SPOs—student post office boxes—are also located in the Union.
Luther College maintains radio station KWLC-AM, and the college's affiliate station, KLSE-FM, is part of the Minnesota Public Radio network. Luther also maintains the largest archaeological research center in Iowa. Vesterheim, the Norwegian-American Museum, is one of the finest ethnic museums in the country; located in downtown Decorah, it provides an invaluable resource for museum and Scandinavian studies.