The Sigma Rho Fraternity (ΣΡ) is a College of Law-based fraternity in the University of the Philippines Diliman. Having been formally organized in 1938, it is the oldest law-based Greek-letter fraternity in Asia. However, it has also expanded its membership base to include undergraduate students, including those studying for degrees in engineering, business, and sports science. It is one of the three fraternities based in the College, the other two being Alpha Phi Beta and Scintilla Juris.