The local fraternity Phi Beta Sigma applied for a charter as a chapter of the Sigma Nu fraternity, and in 1921 the Epsilon Eta Chapter of Sigma Nu was established at UT. The fraternity was established at Virginia Military Institute in 1868 as the Legion of Honor but was kept secret until the announcement of the new society on January 1, 1869—the official date of founding of Sigma Nu. In 1932 Sigma Nu absorbed the UT local Beta Alpha Omega.
The colors of the fraternity are black and gold, and the flower is the white rose. Institutional traditions include the White Rose Ball, Dogpatch Party, and Creole Party. The fraternity’s traditional “yell” was Hi Rickety! / Whoop te doo! / What’s the matter with Sigma Nu? / Hullabaloo! Terrikahoo! Os—kee-sy-kee! / Sigma Nu! Notable alumni of the national organization include Eli Manning, Bear Bryant, and Bob Barker.
In spring 1964 Sigma Nu sold its house at Rose Avenue and Seventeenth Street to the Knoxville Housing Authority for $25,000 as part of the Yale Avenue Urban Renewal Project. The house it built in Fraternity Park was designed by alumnus Al Abernathy of Abernathy and Robinson, and the contractor was another alumnus, Charles Emory. The new chapter room was “in the round,” with the arm of the house connecting the room with the rest of the structure in the shape of the fraternity badge. The modern gray-brick house featured a skylight over the chapter room in the shape of the five points of the blade. The house cost $225,000.
The university required all fraternities to upgrade their houses to meet current fire and safety codes in anticipation of the re-signing of the 50-year ground leases with UT. The Sigma Nu house was razed and rebuilt at a cost of $2.1 million. The house was closed for the 2008–9 year and reopened in 2010.
In 2004 the chapter was suspended pending investigation of a hazing incident. The chapter was reinstated, on probation status for a year, in April 2004, following the investigation that found evidence of hazing but not to the serious extent first thought.