UWO is home to Canada's largest Greek community! There are 6 active NPC groups and 20 active NIC groups. Delta Upsilon was the first fraternity (1931) and Pi Beta Phi was the first sorority (1934).

The most famous Western Ontario DU is Brother Alan Thicke (Growing Pains on ABC) initiated in '67. In 1989, UWO opened a research center for Juvenile Diabetes in his name.

Some familiar names on Western campus belong to Western Ontario Delta Upsilon Alumni David B. Weldon '47 (library), Richard M. Ivey '47 (School of Business), Dr. Peter Fowler (Sports Medicine Clinic) and John Robarts (1939), the former Ontario Premier for whom the Robarts Research Institute is named.

The Collip Building between Middlesex College and the Geology building is named for Dr. James B. Collip, alumnus of Kappa Alpha Society's VOO Chapter, and Former Dean of Medicine at UWO.

Chi Omega Women's Fraternity is the largest NPC group. Its only Canadian chapter was Phi (old) Chapter chartered at Hellmuth Women's College in London ON in 1899 (closed 1900). Hellmuth's was part of Huron College, named for Bishop Isaac Hellmuth who founded "Western University" in 1878.

Each Autumn, Western fans cheer for the Mustangs singing The Western Song (...another Western VICTORY!...), written in the late 1930s by Western Ontario Delta Upsilon alumnus Don Wright.

As of 1999, active members of the Epsilon Omicron Chapter of the Fraternity of Sigma Chi who are undergraduate students at UWO enrolled in any year beyond year one may apply for the award Sigma Chi - Brother Tom Merry Award through Western's Financial Aid Office.